Revival: SE.RA.PH - Challenge Guide: Fallen Angel Cage Part 10 (Kingprotea)

Additional Guides

Enemy Layout

Fatal Battle 1/1

2,000,000

Kingprotea

[Ultra High Difficulty] Cage of the Fallen (10/10) AP - 5

Drops
Rewards	Holy Grail x1

Boss Statistics

Kingprotea
	HP	2,000,000
	LVL	90
	Class	Alter Ego
	NP Bar
	NP Type	AoE
	Actions	Up to 3 per turn
	Traits	Humanoid, Servant, Female, Divine, Giant, Super Giant, Heaven or Earth, Weak to Enuma Elish, Lawful Good

Every Turn		Huge Scale EX: Increase own Max HP by 500,000 [Unremovable]. (Stacks; does not count as an action)
Passive		Cache Clear: At the end of Turn 21, and again every 6 turns (27, 33, 39, etc.), nullify all Max HP buff stacks on self (1 turn) [Max HP temporarily returns to 2,000,000]. Decrease own Damage Resist by 300%, Decrease own Buster, Quick, and Arts Resist by 100%, Decrease own DEF by 100% [Unremovable]. *Note debuffs stack with each Cache Clear! The special Damage Resist / DEF debuff are capped at -100%; Card Resist has no cap.
Turn 1		"...I'm hungry...": Remove debuffs for all enemies. Decrease HP Recovery Amount for all enemies by 90% [Unremovable]. *Can be randomly used after Turn 14.
Turn 7		"Please...embrace me...": Remove debuffs for all enemies (includes unremovable debuffs). Decrease DEF for all enemies by 50% [Unremovable]. *Can be randomly used after Turn 14.
Turn 14		"Please...love me...": Remove debuffs for all enemies (includes unremovable debuffs). Decrease NP Gain for all enemies by 50% [Unremovable]. *Can be randomly used after Turn 14.
Skill 1		Monstrous Strength EX: Increase own ATK (3 turns).
NP		Airavata King Size E Increase own Buster Card effectiveness when [Growth] buff is active by 20% (1 turn). [Activates first] Further increase own Buster Card effectiveness (1 turn). [Activates first] Deals damage to all enemies.

Overview

Although Kingprotea comes without any sort of Break, her HP pool is nothing less than massive, starting at 2,000,000 on the very first turn. She will further increase her Max HP by 500,000 every turn starting from the second turn, without a cap on the amount of Max HP she can get.
This pattern is broken at the end of the 21st turn, where Kingprotea’s Max HP buffs will be disabled for the following turn (22), and she gains various (permanent, stackable) debuffs which would significantly increase the damage she takes. This pattern will then be repeated every 6 turns, meaning that players should prepare to burst Kingprotea on turns 22, 28, 34, and so on.
Kingprotea will also cast three debuffs to the party: HP Recovery Down(1st turn), Defense Down (7th turn), and NP Gain Down (14th turn), with the new debuff overwriting the previous one. After this initial sequence, the debuffs are casted randomly, though NP Gain Down seems to be favored whenever there is a Servant on the field unaffected by any of the three debuffs.
This stage relies heavily on the party’s sustain capability, in most cases requiring a stall of at least 20 turns (unless Kingprotea is defeated on the very first couple of turns). The HP Recovery Down and NP Gain Down debuffs, while a hindrance, are not nearly as dangerous as the Defense Down, which is the stage’s biggest threat aside from Kingprotea’s AoE NP.
In theory, Kingprotea will eventually stack enough debuffs that even parties with the lowest damage outputs will be able to clear the stage (provided they are able to survive up to that point), but it’s recommended to bring along a single-target damage dealer in order to significantly shorten the process and thereby minimize the chance of stray criticals or otherwise poor RNG jeopardizing the run.
The Chaldea Combat Uniform can be used to stack buffs on the main damage dealer on the very first turn, before switching them out for a stall-oriented Servant. The main damage dealer will only be brought in once again at turn 22 (or whenever the time is right) to finish off Kingprotea.

Team Recommendations

Notably, Enkidu might be able to solo the stage under certain situations.
Given enough turns (or offensive buffs), single-target damage dealers from any class except for Foreigner can be used for this stage, with Berserkers having an easier time thanks to their offensive advantage. Jeanne d'Arc (Berserker Alter) is a notably powerful option, though other options such as Lu Bu or Hijikata Toshizo can also work. Other prominent nukers (e.g. Scathach, Sakata Kintoki(Rider)) would also perform great.
Damage supports, such as Scathach-Skadi, Merlin, Tamamo no Mae and Zhuge Liang should be used if available, as they will greatly lessen the amount of stalling needed. Otherwise, alternatives such as William Shakespeare, Helena Blavatsky, and Gilgamesh (Caster) may also be used in their place.
Supports with both sustain and defensive capabilities such as Merlin, Jeanne d’Arc, Mash Kyrielight and Hans Christian Andersen should be prioritized due to the stage’s stalling requirement.
Also important is the capability to defend against Kingprotea’s AoE NP, something which can be provided by one of the above options as well as Servants like David or Tristan.
The Chaldea Combat Uniform Mystic Code is recommended thanks to its Order Change, allowing the main damage dealer to be buffed on the first turn and then switched out, ensuring their safety until the 22nd turn.