This guide is written by GunDelSol, you can check his youtube channel for video guide.
Challenge stages have been introduced and are available for all players that have cleared Chapter 4 Elite stages. Challenge stages do not require stamina, can be attempted as many times as you want per day, but are only available once per account. They impose restrictions on several aspects of your team and are generally difficult.
As I do not purchase heroes, I will only use F2P heroes for completion. I am sure there are multiple teams that can beat each stage even easier than the heroes I have listed, but at the very least, the teams below are possible.
This guide assumes that you have an intermediate grasp of how to complete hero stages (e.g., don't use auto-cast, always manually target your ultimates when possible, save your ultimates for tough spots, don't stack stuns).
Challenge Stage 1-1: Maiden Battle
Requirements:
Can only use a maximum of 4 heroes.
All heroes must survive.
Clear stage with the imposed restrictions (I will be eliminating this requirement from future comments as it is redundant).
Maximum hero level: 1
Maximum rank: 1
Team that can clear: Child of Light, Prima Donna, Snow Queen, Bombin' Goblin
Special notes: Your team composition should usually compose of a front-liner, a healer, a mass AoE damage-dealer, and either single target DPS or mass lockdown. Child of Light provides the front line tank, and his activated ability is a very long AoE stun. Prima Donna will be your only option for healer for a few levels. Snow Queen also provides a very long AoE stun and decent magic damage. Finally, you can choose the AoE damage dealer – I find that Night Raven can get too close sometimes. Sage of Storms could also work, but his activated ability has much less AoE than Bombin' Goblin.
Reward:50 gems
Challenge Stage 1-2: Military Exercise
Requirements:
Can only use a maximum of 4 heroes.
Not more than 1 hero(es) can die.
Maximum hero level: 1
Maximum rank: 1
Team that can clear: Child of Light, Prima Donna, Snow Queen, Bombin' Goblin.
Special notes: None
Reward: 50 gems
Challenge Stage 1-3: Sparring Session
Requirements:
Can only use a maximum of 4 heroes.
Not more than 1 hero(es) can die.
Maximum hero level: 1
Maximum rank: 1
Team that can clear: Child of Light, Prima Donna, Snow Queen, Bombin' Goblin.
Special notes: None
Reward: 50 gems
Challenge Stage 1-3, Trial 1
Requirements:
Heroes can only be: DEX Hero.
Maximum hero level: 7
Maximum rank: 2
Team that can clear: Demon Slayer, Shade, Scarlet Bolt, Night Raven, Tracker
Special notes: None
Reward: 50 gems, Unlock Trial 2
Challenge Stage 1-3, Trial 2
Requirements:
Heroes can only be: STR Hero.
Can only use a maximum of 3 heroes.
Maximum hero level: 7
Maximum rank: 2
Team that can clear: Child of Light, Rose Knight, Soul Forger
Special notes: This level will be impossible until you unlock Rose Knight. She is the only strength hero with a heal. Soul Forger is also not necessary, but I found him to be slightly better than Oath Keeper. You can certainly sub him out.
Reward: 75 gems, Unlock Trial 3
Challenge Stage 1-4: Predator or Prey?
Requirements:
Can only use a maximum of 4 heroes.
All heroes must survive
Maximum hero level: 1
Maximum rank: 1
Team that can clear: Child of Light, Prima Donna, Snow Queen, Bombin' Goblin.
Special notes: None
Reward: 50 gems
Challenge Stage 1-5: Damsel in Distress
Requirements:
Not more than 1 hero(es) can die.
Maximum hero level: 1
Maximum rank: 1
Team that can clear: Death Knight, Child of Light, Snow Queen, Prima Donna, Bombin' Goblin
Special notes: The MOST IMPORTANT part of this fight is to save an interrupt for when the enemy Prima Donna is about to heal. There is a huge wind-up for it, and you can stun her before that gets off. SQ, CoL, or DK can do so. If you do not save a stun for her heal, you will not pass this stage – your heroes do not do enough damage to get through.
Reward: 50 gems
Challenge Stage 1-6: Gurgitator
Requirements:
Can only use a maximum of 4 heroes.
All heroes must survive.
Maximum hero level: 1
Maximum rank: 1
Team that can clear: Child of Light, Sage of Storms, Snow Queen, Prima Donna
Special notes: None
Reward: 50 gems
Challenge Stage 1-6, Trial 1
Requirements:
Kill all Wave 1 enemies within 20s.
Can only use a maximum of 4 heroes.
All heroes must survive.
Stun the Boss at least 2 time(s).
Maximum hero level: 7
Maximum rank: 2
Team that can clear: Child of Light, Prima Donna, Demon Slayer, Incinerator
Special notes: The 20 second first wave requirement is probably the most difficult. You need a lot of AoE damage – Incinerator provides that plus a stun that's needed for the boss.
Reward: 50 gems, Unlock Trial 2
Challenge Stage 1-6, Trial 2
Requirements:
Kill all Wave 1 enemies within 20s.
Can only use a maximum of 4 heroes.
All heroes must survive.
Heroes cannot be: STR Hero.
Maximum hero level: 7
Maximum rank: 2
Team that can clear: Prima Donna, Death Archer, Tracker, Trickster
Special notes: With the lack of STR heroes, you will quickly find that no hero can survive the first round waiting for Prima Donna's heal to build except… Prima Donna herself! Getting hit builds your activated ability rather quickly, so while she will always be near death this stage, she can heal her whole team. The only 4 heroes that allow her to be in front are Tracker, Trickster, Death Archer, and Black Crow. Tracker and Death Archer are needed to clear the first round in 20 seconds, and I found that Trickster works better than Black Crow in the last round.
Reward: 75 gems, Unlock Trial 3
Challenge Stage 1-7: Mutant Tree I
Requirements:
Can only use a maximum of 4 heroes.
All heroes must survive.
Maximum hero level: 2
Maximum rank: 2 (each hero can now use their second ability)
Team that can clear: Child of Light, Sage of Storms, Snow Queen, Prima Donna
Special notes: None
Reward: 50 gems
Challenge Stage 1-8: Elven Trails
Requirements:
Can only use a maximum of 4 heroes.
All heroes must survive.
Maximum hero level: 2
Maximum rank: 2
Team that can clear: Child of Light, Death Knight, Oath Keeper, Prima Donna
Special notes:
1/3: 1-8 is fucking difficult. Get ready. Your three bruisers will all build their ults. Heal with PD in this round so that you can go into the next one with full health.
2/3: This round is much harder than the actual boss. Your goal is to keep the enemy Death Archer stunned as much as possible while you quickly dispatch of the front line. As soon as CoL runs into battle, use his ult to stun the two front liners + enemy Death Archer. As soon as that stun wears off, use OK to clip one of the front liners + DA. Heal with PD when DK gets low, but SAVE HIS ULT. You will have to wait until you clear the front liners to get next to the DA. She'll throw her poison bombs that hurt a lot, but ignore them until she does her backflip that indicates she is about to ult. Freeze her mid-air. When the ice wears off, CoL should be back up to stun her. When that stun wears off, hit her again with OK. Heal with PD every time her heal is ready. You'll be golden if you can head into round 3 after just healing with PD or ready to heal at the start of the next round. NOTE: All of the stuns have a small chance to not affect their targets. I've found that in this round, if any of them fail against DA, it is a lost round. Thus, there is some RNG at play.
3/3: There isn't anything special about this round – if you have survived round 2, you should be able to pass this one. Ult immediately with the heroes as soon as they are ready and make sure all of your stuns hit the boss + as many adds as you can hit.
Reward: 50 gems
Challenge Stage 1-9: The Icy Queen
Requirements:
Not more than 1 hero(es) can die.
Maximum hero level: 2
Maximum rank: 2
Team that can clear: Child of Light, Demon Slayer, Sage of Storms, Snow Queen, Prima Donna
Special notes: 1-9 can also frustratingly difficult. You have to keep the enemy Snow Queen locked down and unable to attack for as long as possible – CoL and SQ do just that (lockdown on a dangerous foe seems to be the motif throughout the stages). Demon Slayer was an interesting addition and can do a ton of damage to the adds in the final round while you cycle through your CC. He will eventually die, but if you can keep your CoL alive, you will win.
Reward: 50 gems
Challenge Stage 1-9, Trial 1
Requirements:
Can only use a maximum of 3 heroes.
Must use Snow Queen
Snow Queen must survive.
Maximum hero level: 8
Maximum rank: 2
Team that can clear:Child of Light, Prima Donna, Snow Queen
Special notes:Very easy level overall.
Reward:50 gems, Unlock Trial 2
Challenge Stage 1-9, Trial 2
Requirements:
Can only use a maximum of 3 heroes.
Must use Snow Queen
Total Hero HP cannot fall below 30% at any time.
Maximum hero level: 8
Maximum rank: 2
Team that can clear: Child of Light, Prima Donna, Snow Queen
Special notes: While the first two rounds shouldn't be difficult, the last round can cause some issues if you do not stack your stuns correctly. The requirement also makes it seem like the total hp pool of all your heroes combined cannot fall below 30%, but as you will quickly learn, if ANY hero gets below 30%, you will lose.
Reward: 75 gems, Unlock Trial 3
Challenge Stage 1-10: Mutant Tree II
Requirements:
Can only use a maximum of 4 heroes.
Maximum hero level: 2
Maximum rank: 2
Team that can clear: Child of Light, Demon Slayer, Snow Queen, Prima Donna
Special notes: 1-10 is relatively easy. This is the first stage without a death restriction, so it behaves like a normal stage where the only thing that matters is the last man standing.
Reward: 50 gems
Challenge Stage 1-11: Feeling the Heat
Requirements:
Can only use a maximum of 4 heroes.
Maximum hero level: 2
Maximum rank: 2
Team that can clear: Child of Light, Demon Slayer, Snow Queen, Prima Donna
Special notes: Surprise visit by Bombin' Goblin at the end there. Try to save one interrupt for him, because he can kill Prima Donna faster than she can heal otherwise.
Reward: 50 gems
Challenge Stage 1-12: A Lord's Undertaking
Requirements:
Not more than 1 hero(es) can die.
Maximum hero level: 3
Maximum rank: 2
Team that can clear: Child of Light, Demon Slayer, Snow Queen, Prima Donna, Bombin' Goblin
Special notes: None
Reward: 50 gems
Challenge Stage 1-12, Trial 1
Requirements:
Can only use a maximum of 3 heroes.
Boss must be the 1st to die.
Maximum hero level: 9
Maximum rank: 2
Team that can clear: Rose Knight, Shade, Scarlet Bolt.
Special notes: Rose Knight provides all the sustain you will need in this stage. The Bombin' Goblin reinforcement can be skipped in Round 2 by eliminating the three back line enemies before killing the front two.
Reward: 50 gems, Unlock Trial 2
Challenge Stage 1-13: Mutant Tree III
Requirements:
Can only use a maximum of 4 heroes.
Maximum hero level: 4
Maximum rank: 2
Team that can clear:Child of Light, Demon Slayer, Snow Queen, Prima Donna
Special notes:Your front liners might come close to dying a few times. Timing with the stuns and heals is crucial in this stage.
Reward:50 gems
Challenge Stage 1-14: Rare Species
Requirements:
Can only use a maximum of 4 heroes.
Not more than 1 hero(es) can die.
Maximum hero level: 5
Maximum rank: 2
Team that can clear: Child of Light, Death Knight, Snow Queen, Prima Donna
Special notes: Death Knight might die during this stage, but as long as he is the only one, that is fine. Much like 1-8, the second round is harder than the first. You'll just want to keep the enemy Tracker locked down as much as possible.
Reward: 50 gems
Challenge Stage 1-15: Mythical Beast
Requirements:
Can only use a maximum of 4 heroes.
Not more than 1 hero(es) can die.
Maximum hero level: 5
Maximum rank: 2
Team that can clear: Child of Light, Oath Keeper, Tracker, Prima Donna
Special notes: None
Reward: 50 gems
Challenge Stage 1-16: Intruder Alert!
Requirements:
Can only use a maximum of 4 heroes.
Maximum hero level: 5
Maximum rank: 2
Team that can clear: Child of Light, Oath Keeper, Snow Queen, Prima Donna
Special notes: Even though the final video shows both CoL and PD dying, they didn't in the few trial runs leading up to this. Nevertheless, there is no death restriction on this level.
Reward: 50 gems
Challenge Stage 1-17: Lurking in the Dark
Requirements:
Can only use a maximum of 4 heroes.
Maximum hero level: 5
Maximum rank: 2
Team that can clear: Child of Light, Oath Keeper, Snow Queen, Prima Donna
Video
Special notes: None
Reward: 50 gems
Challenge Stage 1-18: The Fittest Survives
Requirements:
Not more than 1 hero(es) can die.
Maximum hero level: 6
Maximum rank: 2
Team that can clear: Child of Light, Oath Keeper, Snow Queen, Prima Donna, Tracker
Special notes: None
Reward: 50 gems
Challenge Stage 2-1: Trials of Elements
Requirements:
Can only use a maximum of 4 heroes.
Maximum hero level: 7
Maximum rank: 2
Team that can clear: Child of Light, Snow Queen, Prima Donna, Tracker
Special notes: None
Reward: 50 gems
Challenge Stage 2-2: Stability
Requirements:
All heroes must survive.
Maximum hero level: 8
Maximum rank: 2
Team that can clear: Child of Light, Snow Queen, Prima Donna, Tracker, Bombin' Goblin
Special notes: None
Reward: 50 gems
Challenge Stage 2-3: Wesley's Test
Requirements:
Can only use a maximum of 3 heroes.
All heroes must survive.
Maximum hero level: 9
Maximum rank: 2
Team that can clear: Child of Light, Prima Donna, Tracker
Special notes: This level is insane. One of my guildmates recommended a team in which you replace Tracker with Demon Slayer, but I couldn't get that to work. The key in the third round is to survive long enough for Oath Keeper to use his ult. Switch off between healing when CoL gets low to using CoL's ult to buy enough time for Wesley's ult. CoL will have to have enough health to survive, which will allow PD to heal (you can hear me frantically clicking on this part).
Additionally, you'll notice me not using CoL's ultimate immediately upon getting it sometimes. If you use his ultimate when the round first starts, you will waste the majority of his first invulnerability period while the enemies are stunned. You need every bit of time to allow PD to recharge her heal. Good luck!
Reward: 50 gems
Challenge Stage 2-4: Jeering Arges
Requirements:
Can only use a maximum of 4 heroes.
All heroes must survive.
Maximum hero level: 9
Maximum rank: 2
Team that can clear: Child of Light, Prima Donna, Snow Queen, Tracker
Special notes: None
Reward: 50 gems
Challenge Stage 2-5: Dwarfed by Dwarves
Requirements:
Not more than 1 hero(es) can die.
Maximum hero level: 10
Maximum rank: 2
Team that can clear: Child of Light, Prima Donna, Oath Keeper, Rose Knight, Tracker
Special notes: None
Reward: 50 gems
Challenge Stage 2-6: Tattler the Trickster
Requirements:
Not more than 1 hero(es) can die.
Maximum hero level: 11
Maximum rank: 2
Team that can clear: Child of Light, Prima Donna, Oath Keeper, Rose Knight, Tracker
Special notes: None
Reward: 50 gems
Challenge Stage 2-7: Treasure Hoarder
Requirements:
Can only use a maximum of 4 heroes.
Not more than 1 hero(es) can die.
Maximum hero level: 10
Maximum rank: 2
Team that can clear: Child of Light, Prima Donna, Rose Knight, Tracker
Special notes: None
Reward: 50 gems
Challenge Stage 2-8: To Arms
Requirements:
Can only use a maximum of 4 heroes.
All heroes must survive.
Maximum hero level: 10
Maximum rank: 2
Team that can clear: Child of Light, Prima Donna, Rose Knight, Tracker
Special notes: None
Reward: 50 gems
Challenge Stage 2-9:
Team that can clear: Prima Donna, Child of Light, Death Knight, Tracker, Incinerator
Challenge Stage 2-10:
Team that can clear: Prima Donna, Child of Light, Bombin Goblin, Tracker, Incinerator
Challenge Stage 2-11:
Team that can clear: Prima Donna, Child of Light, Bombin Goblin, Rose Kngiht, Snow Queen
Challenge Stage 2-12:
Team that can clear: Prima Donna, Child of Light, Bombin Goblin, Rose Kngiht, Snow Queen
Challenge Stage 2-13:
Team that can clear: Prima Donna, Child of Light, Rose Kngiht
Challenge Stage 2-14:
Team that can clear: Prima Donna, Child of Light, Tracker, Rose Kngiht, Snow Queen
Challenge Stage 2-15:
Team that can clear: Prima Donna, Child of Light, Trickster, Rose Kngiht, Night Raven
Challenge Stage 2-16:
Team that can clear: Prima Donna, Child of Light, Rose Kngiht, Incinerator
Challenge Stage 2-17:
Team that can clear: Prima Donna, Child of Light, Rose Kngiht, Incinerator, Snow Queen
Challenge Stage 2-18:
Team that can clear: Prima Donna, Child of Light, Rose Kngiht, Night Raven, Bombin Goblin