Once you reach the Resurgent Dragon phase, you'll face the final Boss: Cypreum, the Undyne Inferno. The main difficulty of this Challenge lies in countering the Boss's various Debuff mechanics. This guide will break down its skills and offer recommended team compositions.

Sample Lineup 1

Team Composition: Felosia + Beldelle + Fredegonda + Shinnah + Zhorak●Team Aura/Familiar
We recommend using Beldelle's Attack Aura with the Stoneborn Familiar to maximize your team's damage output. If survivability is an issue, consider switching to the Long-Eared Deer.
●Skill Timing Reference●Notes
1. If you're struggling with survivability, consider replacing Zhorak with a survival-oriented Support hero to keep your team alive.
2. Position your heroes as shown. Stack Felosia's Resistance to over 400 to activate her Stand United Talent. This will allow her to share Resistance with all allies.
 
●Hero Replacement Reference                                                                                                                                                                                     

Replenish Ally Ice Crystal Increase Ally Damage Output	Secondary Damage Dealer Increase Ally Damage Output	Inflict Ice Crystal Increase Ally Damage Output	Main Damage Output
Replacement Reference
Inflict Ice Crystal Increase Ally Damage Output	Secondary Damage Dealer	Inflict Ice Crystal	Main Damage Output

 

Build Reference

●Key Attribute Requirements
Felosia: Resistance > 400; stack Enlightenment and Skill Haste as high as possible.
Beldelle, Shinnah, Zhorak, Fredegonda: Resistance > 220;
Shinnah: Accuracy > 300
 
●Gear Reference●Talent Reference 

Sample Lineup 2

Team Composition: Khrysos + Journ + Karf + Durem + Paixton●Team Aura/Familiar
This team has no available Aura. The Tressym Familiar is recommended to maximize team damage output. If survivability is an issue, consider switching to the Long-Eared Deer.
●Skill Timing Reference●Notes
1. When using Journ, stack enough Resistance to prevent him from being inflicted with Recharging Speed Penalty, and also stack Skill Haste as high as possible to increase Ultimate Energy for allies.
2. Khrysos can be replaced by Synarell or Scaarr.
●Hero Replacement Reference                                                                                                                                                                                                               

Healing, Shield Attack Penalty Dispel Debuffs Dispel Buffs	Attack Penalty Increase Ultimate Energy Dispel Buffs	Inflict Burn Secondary Damage Dealer	Inflict Burn	Main Damage Output
Replacement Reference
Increase Ultimate Energy Healing, Shield	Healing Attack Penalty Dispel Debuffs	Inflict Burn Secondary Damage Dealer	Inflict Burn	Main Damage Output

Build Reference

●Key Attribute Requirements
Khrysos, Paixton, Karf, Journ: Accuracy > 300.
Journ: Resistance > 300; also stack Skill Haste as high as possible.
Durem: Accuracy > 170.
 
●Gear Reference●Talent Reference

Sample Lineup 3

Team Composition: Reytah + Oggok + Szecedith + Rook + Sacredeia●Team Aura/Familiar
We recommend using Rook's Attack Aura with the Tressym Familiar to maximize the team's damage output.
●Skill Timing Reference●Notes
1. Position your heroes as shown. Stack Oggok's Resistance to over 400 and activate the Stand United Talent, allowing him to share Resistance with nearby allies. Oggok can be replaced with Blah Blah.
 
●Hero Replacement Reference                                                                                                                                                                                                               

Healing Extend Debuffs Dispel Debuffs Defense Up	Healing Attack Penalty Dispel Debuffs	Secondary Damage Dealer Apply Corrosion	Increase Ally Damage Output	Main Damage Output
Replacement Reference
Healing Attack Penalty Dispel Debuffs	Healing Debuff Immunity	Apply Corrosion	Increase Ally Damage Output	Main Damage Output

Build Reference

●Key Attribute Requirements
Oggok: Skill Haste > 90, Resistance > 400. For other stats, prioritize stacking Enlightenment and Attack.
Other heroes: Resistance > 220.
Reytah: Accuracy > 300, Skill Haste > 40.
Sacredeia: Accuracy > 260.
 
●Gear Reference 
●Talent Reference

 Sample Lineup 4

Team Composition: Talethia + Diantha + Lincos + Anneliesis + Shahla●Team Aura/Familiar
We recommend using Diantha's Attack Aura with the Tressym Familiar to maximize the team's damage output.
●Skill Timing Reference●Notes
1. If survivability is an issue, you can replace Lincos with any survival-oriented Support.
2. Adjust your gear to ensure Talethia has the highest Attack and Crit Damage on the team. This will make her the reliable target for skill buffs from Lincos and Shahla.
 
●Hero Replacement Reference                                                                                                                                                                                                  

Healing, Shield Dispel Debuffs Dispel Buffs		Main Damage Output	Increase Ally Damage Output Restore Aura Energy	Increase Ally Damage Output Restore Aura Energy
Replacement Reference
Healing Debuff Immunity	Healing, Shield Dispel Buffs Defense Up	Main Damage Output	Increase Ally Damage Output Restore Aura Energy	Increase Ally Damage Output Restore Aura Energy

Build Reference

●Key Attribute Requirements
Anneliesis, Diantha: Accuracy > 300
 
●Gear Reference 
●Talent Reference

Sample Lineup 5

Team Composition: Maashtur + Nastjenka + Guinavivre + Kurvida + Tharivol●Team Aura/Familiar
We recommend using Nastjenka's Attack Aura with the Stoneborn Familiar to maximize your team's damage output. If survivability is an issue, consider switching to the Long-Eared Deer.
●Skill Timing Reference●Notes
1. Maashtur can be replaced by heroes such as Irmoush, Acilia, or Nathaniel. If this swap prevents you from dispelling the boss's Power of Dragon Rage in time, you can replace Tharivol with Divine Ascetic. In that case, have Kurvida equip Witch's Remains.
 
●Hero Replacement Reference                                                                                                                                                                                                               

Healing, Shield Ultimate Down Multiple Buffs	Main Damage Output Combo Attack	Secondary Damage Dealer Combo Attack	Secondary Damage Dealer Increase Ally Damage Output	Secondary Damage Dealer High-Frequency Basic Attack
Replacement Reference
Healing, Shield Dispel Debuffs	Main Damage Output Combo Attack	Secondary Damage Dealer High-Frequency Basic Attack	Secondary Damage Dealer Increase Ally Attack Speed	Secondary Damage Dealer Increase Ultimate Energy

 

Build Reference

●Key Attribute Requirements
Maashtur and Tharivol: Accuracy > 300.
For Maashtur, stack as much HP and Skill Haste as possible.
Tharivol: Crit Rate ≥ 100%.
Kurvida: Accuracy > 260.
 
●Gear Reference●Talent Reference

Sample Lineup 6

Team Composition: Ethyreis + The Dark Lady + Irzillas + Lelwanis + Bernade●Team Aura/Familiar
We recommend using Irzillas's Attack Aura with the Tressym Familiar to maximize the team's damage output.
●Skill Timing Reference●Notes
1. If you don't have Ethyreis or The Dark Lady, you can substitute them with heroes like Torrin and Astaion, but your team's damage output will be lower.
2. Position your heroes as shown. Stack Ethyreis's Resistance above 400 to activate the Stand United Talent, allowing Ethyreis to share Resistance with nearby allies.
 
●Hero Replacement Reference                                                                                                                                                                                                               

Healing Dispel Debuffs Damage Reduction	Attack Penalty Dispel Buffs Buff Prohibition Boost Ally Stats	Increase Ally Damage Output	Increase Ally Damage Output Spawn Summoned Unit	Main Damage Output
Replacement Reference
Healing Debuff Immunity Defense Up	Healing Dispel Buffs Buff Prohibition	Secondary Damage Dealer	Increase Ally Damage Output Spawn Summoned Unit	Main Damage Output

Build Reference

●Key Attribute Requirements
Ethyreis: Resistance > 400; stack Enlightenment and Skill Haste as high as possible.
Bernade and Irzillas: Resistance > 220
The Dark Lady and Bernade: Accuracy > 300
 
●Gear Reference●Talent Reference