Guide
How the kit works
Before combat, Enkidu creates a dimension for 10 seconds and stops enemies inside it. Attack an affected enemy to bring all affected enemies into battle, deal Lightning DMG equal to 200% of Gilgamesh's ATK to all enemies and gain 3 Interest. Only one allied Dimension Effect can exist at a time.
At first, Gilgamesh automatically uses Halfhearted Blow at the start of his turn. Through "Amuse Me to the Fullest", each action by another ally grants him 1 Interest, and each point held increases his SPD by 10%. The first time he reaches 10, he enters a state that lasts for the battle and makes him use only Skill. Each Skill then clears his Interest.
Gate of Babylon deals 280% of his ATK to its target and 140% to adjacent enemies. It also grants King's Acknowledgement for 3 turns, letting Gilgamesh ignore 30% of enemy DEF when dealing damage. An ally's Ultimate grants King's Burden, increasing his Ultimate DMG by 40% for 3 turns.
Enuma Elish deals 400% of his ATK to all enemies, followed by 10 hits against random enemies, each worth 100% of his ATK. His own Ultimate grants 2 Interest. Another ally's Ultimate grants 2 Interest and restores Energy equal to 30% of the Energy that ally consumed.
With Saber, "I Grant You Permission To Strike" counts their attacks. At 8 attacks, the pair launch a Joint Follow-Up ATK and reset the tally. Gilgamesh gains 3 Interest; Saber restores 120 Energy and her next Ultimate deals 200% of its original DMG.
Build and why
For relics, Scholar Lost in Erudition is the first choice. Its four-piece effect raises Skill and Ultimate DMG by 20%, then raises the next Skill's DMG by another 25% after an Ultimate. The two-piece bonus gives 8% CRIT Rate.
The Ashblazing Grand Duke is an alternative centered on Follow-Up ATK. Genius of Brilliant Stars is another option: its four-piece effect ignores 10% DEF, or another 10% against Quantum Weakness, though its two-piece Quantum DMG bonus does not help Gilgamesh's Lightning attacks.
For a planar set, Cosmic Life Sciences Institute rewards Max Energy above 200 with more DMG, up to 32%. City of Converging Stars is an option for a Follow-Up team, while Izumo Gensei and Takama Divine Realm gives CRIT Rate when another teammate follows Destruction.
Use CRIT Rate or CRIT DMG on the body, SPD or ATK Percentage on the feet, Lightning DMG Boost or ATK Percentage on the sphere, and ATK Percentage or Energy Regeneration Rate on the rope. Look for CRIT Rate, CRIT DMG, ATK Percentage and SPD substats in that order.
I Am As You Behold is the first Light Cone choice: it gives ATK and Energy Regeneration Rate, boosts Ultimate DMG based on Energy consumed and grants allies CRIT DMG. A Thankless Coronation gives CRIT DMG and an ATK boost on Ultimate; its extra Energy and ATK effects require at least 300 Max Energy. Thus Burns the Dawn is another option with SPD, DEF ignore and a temporary DMG boost after Ultimate.
Leveling priority
Follow the game's order: Enuma Elish, Gate of Babylon, "Amuse Me to the Fullest", then Halfhearted Blow. The Ultimate hits every enemy and adds ten random hits, while the Skill becomes his regular attack after the Interest threshold. Basic comes last because it is used at the start of battle.
For maximum ascension, you need 308,000 Credit, 65 Thunder Strum, and 15 each of Extinguished Core, Glimmering Core and Squirming Core.
For all skills, the listed total is 3,000,000 Credit, 8 Tracks of Destiny, 18 Four Phases, Crossing the River to Check the King, 69 Sixen, King-Rook Fork, 139 Omnicolor, Fool's Own, 12 Guardian's Lament, 41 Extinguished Core, 56 Glimmering Core and 58 Squirming Core.
Eidolons worth it
He Who Saw the Deep is a good first upgrade to consider. While King's Acknowledgement is active, its DEF ignore applies to teammates too, Gilgamesh gains 60% ATK, and each Skill restores 40 Energy.
Wisdom That Encompassed All is another useful option: it grants 5 Interest on entering combat and another 5 when he uses Ultimate. It also raises the Skill multipliers against the primary and adjacent targets.
For a deeper investment, Soul That Bore Friendship adds Ultimate bounce damage and gives allies 20% All-Type RES PEN. Ally Ultimates also build Golden Rule points, which Gilgamesh consumes to increase his Ultimate CRIT DMG.
If you stop before E6, E3 through E5 can wait. E3 and E5 raise skill levels, while E4 gives 20% Energy Regeneration Rate; they are required along the way to E6.
Teams
Saber is the first teammate to consider. Their attacks build the shared tally for "I Grant You Permission To Strike", giving Gilgamesh Interest and helping Saber use a stronger Ultimate. Together they deal Lightning and Wind DMG.
Other allies' actions build Interest, and their Ultimates give Gilgamesh Interest, Energy and an Ultimate DMG boost. In return, he gives allies ATK and CRIT DMG while he is on the field. Allies with Max Energy above 140 receive a larger bonus.
Common mistakes
Do not expect to choose Skill on Gilgamesh's first turn. He starts with automatic Basic ATKs and needs 10 Interest to enter his permanent Skill state. Remember that each Skill clears the Interest he holds.
Do not treat the team's Ultimates as separate from his rotation. They grant him Interest and Energy, and King's Burden raises his Ultimate DMG for 3 turns.
Check set and Light Cone conditions before building around them. Cosmic Life Sciences Institute needs Max Energy above 200 for its DMG increase, and A Thankless Coronation needs at least 300 Max Energy for its extra effects. The Quantum DMG from two pieces of Genius of Brilliant Stars does not strengthen his Lightning attacks.
