FGO Summer 2025 - Challenge Guide

Enemy Layout

Requirements: Clear Epilogue + Final Singularity: Solomon. Unlocks ~Day 10.

Boss Statistics

Overview

• Help give Cnoc na Riabh some feedback on her work in the Challenge Quest of the Summer 2025 event, showcasing her totally not-an-obsession with Saberfaces as she piles on a plethora of Saberface fanworks (enemies) for you to plow through!
• Only Cnoc na Riabh needs to be defeated to clear this quest! She is a break bar Foreigner (375k, 462k HP). All other enemies are entirely optional, but defeating them first will appease the boss can make the boss's 2nd HP bar effects a bit easier to deal with. However, if a team has enough firepower, they can burst through her defenses to end the battle more quickly and skip the flood of Altriaface fanfiction.
• The boss starts with permanent massive 800,000 Damage Cut, Debuff Immunity, self Stun (cannot act), and a buff that causes anyone who hits her with an NP to lose 2 of their latest offensive buffs.
• The damage cut is flat, so if Masters deal enough damage, it is still possible to circumvent this and skip to her second HP bar, although she will have more threatening effects if this is done.
• Her break effect comes in two varieties, depending on whether all other enemies are defeated or not.
• If all others are defeated first, the moment they are defeated, she happily asks for feedback on her fan works, in which she removes her starting permanent buffs/debuffs, heals herself by 100k HP, and gets a debuff that makes her take increased damage from Saberfaces. This might be because she's most vulnerable to criticism from Saberfaces, given they are the main subject of her fan works. After break, she gains just 2 NP charge per turn (instead of full NP), and has a small unremovable Crit Rate buff.
• If at least one other enemy is still alive, her break effect turns into a more threatening one. She instead removes all buffs from the party, gains MAX NP Gauge every turn, has a large ATK +50% buff, and unremovable Guts that works 2 times, with 10% HP recovery on activation. Even if you do finish off the last of her allies at this point, these effects will stay active.
• The Saberface allies of hers are all optional, and represent the fan works made by Cnoc na Riabh that the Master needs to read defeat. Each have an effect that triggers when they enter the field:
• Altria Pendragon: Gets +1 NP charge per turn and a small Buster buff.
• Altria Pendragon (Santa Alter): Debuffs ATK by 20% when normal attacking, while also buffing the target's Star Drop Rate.
• Altria Pendragon (Lily): Buffs own Crit Rate, inflicts Nullify Buff (2 times, 5 turns) and buffs ATK for the party.
• Altria Pendragon (Ruler): Every turn, randomly either gains +2 NP Gauge, ATK +30%, or 1-time, 1-turn Invincibility.
• Altria Pendragon (Lancer Alter): Buffs Debuff Resist and gives Ignore Invincible to their allies.
• Mysterious Heroine XX: Gets 3-hit Invincibility, and 3-turns of Taunt.
• Mysterious Idol X (Alter): Can inflict Charm (30%) when normal attacking, and every turn debuffs Charm Resist.
• Altria Caster: This is Cnoc na Riabh's rendition of Altria Caster, who has the highest number of effects, reflecting the proportional fondness Cnoc na Riabh has for her. This is a sign of extremely high quality fan fiction; she is definitely not written as a Mary Sue.
• Anti-Enforcement DEF to her allies (2 times, 5 turns).
• DEF +30% for her allies (5 turns).
• Special ATK vs Divine Spirit +50% to self (5 turns).
• Burn when normal attacking for self (5 turns). Yes, according to Cnoc na Riabh, Altria Caster has some sick burns.
• ATK +10% when hit for self (5 turns).
• Ignore Invincible for self (5 turns).
• 5,000 HP Regen per turn for self (5 turns).
• Quick +50% for self (5 turns).
• Master Skills recover 2x as quickly (5 turns). [Demerit]

Team Recommendations

• Alter Ego or Foreigner Damage Dealers, especially Single-Target ones, are preferred for this encounter due to their offensive Class Advantage against the primary boss, Cnoc na Riabh. Since the other enemies are optional, damage dealt to them is less important, particularly if Masters wish to speed run this encounter.
• Cnoc na Riabh herself is a pretty decent option for this battle, since she is a Foreigner and has Class Advantage against herself.
• If planning to only defeat the boss and ignore the rest of the Saberfaces, running a second damage dealer that either starts in the backline or is swapped out to the backline before breaking her first HP bar will make sure there's enough firepower to bring down the boss quickly during her second HP bar, since she will otherwise fire an NP every turn, making it difficult to survive for long. The first video link shows an example of this.
• NP Gauge and Damage Supports are helpful as usual, giving the damage dealer more buffs to take out the boss more quickly. With enough offensive buffs on the damage dealer, Masters can entirely skip dealing with any of the Saberface enemies.

• The Event Damage CE Apart, but Together is highly recommended for the damage dealer during this Challenge Quest. Please note that the bonuses provided by this CE are maximized by finishing all Delivery/Errand quests for every club, so clearing all of them before attempting this is highly suggested.

Video Links

• Note that these videos are not affiliated with GamePress, but showcase some lineups that are effective in clearing the final challenge. These can serve as a good reference for how to rotate skills during this quest or simply to have a look at the encounter before diving in.
• Welfare 2 turn clear: Mecha Eli + Mecha Eli MkII + Oberon, backline Chen Gong, Da Vinci Ruler, Cnoc na Riabh (2 turns)
• Alternative setup: Chen Gong, Mecha Eli, Oberon, backline MHXX NP5, Cnoc na Riabh, Gil Caster (2 turns)
• Meltryllis NP1 w/ Skadi Ruler, Support Merlin, Assassin of the Nightless City, Elisabeth Bathory, Merlin (2 turns)
• Cnoc na Riabh w/ 2x Castoria, no backline (12 turns)
• For fun: Osakabehime (NP5 lv120) solo fanbook review (51 turns)

Quick Servant Suggestions