Boss Guide: Ch21-3 (Olympus)

Mandatory NPC Support: Romulus=Quirinus Lv100 NP5 10/10/10

	Mandatory Frontline: Mash Kyrielight
Passive		Athena Klironomia: Increase own Quick, Buster and Arts cards effectiveness by 15%, DEF by 20%, and Guts (1 time, 1,000 HP Revival). [Permanent, Unremovable].
Passive		Conceptual Armament Aegis (True): Increase own Resistance to all Attacks by 30% and grant 500 Damage Cut to self [Unremovable].

Field Effects:
Battle Start		Supreme God Quirinus's Blessing: Remove all the effects of [Anti-Star Type Attack: Titanomachy], [Battle of Olympia] on Zeus. Remove class offensive disadvantage of allied Servants toward Ruler enemies.
Field Effect every turn:
Effect 1		Macarios's Support "Artillery Mystic Code": Decrease all enemies' HP by 1,500 and Decrease their ATK by 10% (1 turn).
Effect 2		Adele's Support "Recovery Mystic Code": Recover all allied Servants' HP by 1,000 and remove one debuff.

Special Mystic Code

Mystic Code: Ares, God of War Mystic Code skills will be replaced by three new skills during this encounter:
Skill 1		War God's Sword Lv 10: Decrease an enemy's HP by 10,000. Switch to the next enemy in order (Zeus -> Zeus Uranus -> Zeus Gaia -> Zeus). Decrease all parts of Zeus' DEF by 100% (3 turns). Cooldown: 5 turns.
Skill 2		Crimson Strike Lv 10: Decrease an enemy's HP by 10,000. Switch to the next enemy in order (Zeus -> Zeus Uranus -> Zeus Gaia -> Zeus). Decrease all parts of Zeus' NP Bar by 2. Cooldown: 5 turns.
Skill 3		War God's Roar Lv 10: Remove all buffs on all parts of Zeus. Increase all allied Servants' ATK by 50% (1 turn) and increase all allied Servants' NP Gauge by 20%. Cooldown: 8 turns.

• This faceoff against Zeus has several unique mechanics only present in this encounter. Zeus himself has three Ruler-class parts, with his main part having 3 break bars. Mystic Code skills will be replaced with a special new set of three skills as well. This battle is less difficult and moreso about understanding the mechanics of the encounter.
• Romulus Quirinus is a mandatory NPC Support. He is a welcome addition, being capable of holding his own in this encounter.
• Mash (Ortinax) is mandatory on the front line. She comes with decent DEF and damage resistance passives, and a 1-time Guts.
• Zeus has three parts total, only one of which will be active. The inactive parts of Zeus cannot be targeted, nor can they be hit by an AoE Noble Phantasm. The only way to switch which part is being targeted is to use the special Mystic Code skills. Zeus can otherwise switch which parts are active on his own.
• Only the main part of Zeus (with 3 break bars) needs to be defeated.
• Zeus starts with high damage Resistance, which are removed when his side parts (Uranus and Gaia) are defeated. The battle will start with the main Zeus part being active, so the Mystic Code skills will be needed to switch off the main part of Zeus to take out the side parts.
• Zeus deals a minor damage bonus to Star attribute Servants. This passive is unremovable.
• Zeus and all parts are immune to Poison, Burn, Curse, Charm, and various delayed Mental Debuffs (such as Terror, Confusion).
• Zeus's two parts have different sets of skills:
• Uranus - Primarily offensively oriented, this part can give main Zeus the following buffs:
  • ATK + Critical Strength buffs (1 time).
  • Invincible and Damage Plus 3000 (1 time).
  • Charge NP Bar by 1, NP Damage buff (1 time).
• Gaia - Primarily defensively oriented, this part can give main Zeus the following buffs:
  • Buster Res +50% (3 times) and Damage Cut by 3000 (1 time).
  • Arts Res +50% (3 times) and DEF +50% (1 time).
  • Quick Res +50% (3 times) and Stun Immune (1 time).
• Note that multiple parts of Zeus can activate their NP on the same turn if their NP bars are full. During these turns, the side parts will always go first, and switch to main Zeus, so that it ends with the main Zeus part being active.
• All Zeus parts have AoE NPs, with relatively minor debuffs that accompany the heavy damage it deals to the party.
• Zeus's main part has an array of skills, each of which have varying threat:
  • ATK/Crit Damage/NP Damage self buffs.
  • Substantial self DEF and Damage Cut buffs.
  • Stun on a target (turn), which then later can stun all allies except the original stunned target on the next turn.
  • Evade on self for a turn.
  • Confusion (Skill Seal each turn) and Debuff Resist down debuffs on the party.
• Zeus can also resurrect his side parts, usually immediately before he uses his Noble Phantasm.
• All parts of Zeus can randomly choose to use a skill that switches out the active part of Zeus.
• 1st Break: Skill Seal + NP Seals the party for a turn.
• 2nd Break: Charges own NP Bar to MAX.

• Use the special Mystic Code skills liberally! They will help a great deal during the encounter. The other parts of Zeus need to be defeated first to remove the main part of Zeus's damage resist buffs.
  • Start with Skill 1 to switch off main Zeus and inflict a DEF debuff. Defeat the side part of Zeus ASAP.
  • Use Skill 2 after defeating the first part, when it switches back to main Zeus. This skill additionally decreases Zeus's NP bar by 2, so avoid using it in situations where this effect is wasted if possible.
  • Skill 3 can be used anytime, although ideally it is used to top off a damage dealer's NP bar with its 20% NP Gauge Up effect. It will also remove all of Zeus's buffs and buff all allies' ATK for a turn.
• Avenger Damage Dealers are a good option for this encounter to deal with Zeus, who is Ruler Class.
• Damage / NP Gauge Support for the damage dealer is the best option to occupy the remaining team slots, with Skadi, Merlin, Tamamo, and Waver all being excellent options as usual depending on the damage dealer's card color.
• Team composition is otherwise somewhat restricted, given that two slots are taken up with a mandatory frontline Mash and NPC Support Romulus Quirinus. Even so, provided the mechanics of the boss are understood (kill the side parts before focusing the main part, and watch out for the 2nd break's full NP gauge), the boss should be relatively straight forward.

• 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.
  • Edmond Dantes w/ Chiron, Mash, Carmilla Rider, Boudica, and NPC Quirinus (3 turns), card luck required.
  • Avenger of Shinjuku NP3 w/ Mash, Skadi, Chen Gong, Asclepius, and NPC Quirinus (4 turns)
  • Jeanne Alter NP1 w/ Mash, Chen Gong, Waver, Reines, and NPC Quirinus (8 turns)
  • Low rarity only w/ NPC Romulus Quirinus (Mash, Chen Gong, Mozart, Hans), warning, be ready for a long battle (57 turns)