Arataki Itto is a Geo DPS Character who takes advantage of his Burst's ATK boost and Geo infusion to deal significant damage during its uptime. His combos involve stacking and unleashing his Charged Attacks, named Arataki Kesagiri. Arataki Kesagiri consumes no stamina and can be cast continuously as long as he has Superlative Superstrength stacks. Superlative Superstrength is capped at 5 stacks at any given time, and Arataki Itto gets those stacks when his 2nd and 4th Normal Attack string hits an enemy. Activating his Burst allows his 1st and 3rd Normal Attack to also generate stacks. Arataki Itto's Skill deals damage to enemies on cast and summons a taunt, Ushi, which is considered a Geo Construct. This initial cast damage grants Arataki Itto 1 Superlative Superstrength stack, and upon Ushi leaving the field, Arataki Itto is granted another stack. When Ushi takes damage, Arataki Itto gains a stack (capped at 1 stack per 2 seconds). Arataki Itto's Burst converts his Normal and Charged Attacks into Geo DMG, increases Arataki Itto's Normal Attack Speed and converts a portion of Arataki Itto's current DEF to ATK.
Regarding Weapon Choices:
Serpent Spine: This weapon scales great with refines on Arataki Itto, making it way better than similar ranking options at [R5]. When using , stacks are prioritized over stacks due to their conflicting nature in gaining stacks (On-Field vs Off-Field).
Whiteblind: Your rotations often start with 1 stack of this weapon, and due to Arataki Itto's Burst snapshotting DEF on cast, you're unable to take advantage of further DEF% from the stacks.
Skyward Pride: Can be a great or bad weapon for Arataki Itto depending on your ER needs. The less Energy Recharge you need (due to particle generation from your party members or ER from subs), the less useful this weapon becomes.
Regarding Artifact Choices:
Sets
Retracing Bolide (4): This set grants you an additional 40% Normal and Charged Attack DMG when shielded. Crystallize can be unreliable so a consistent shielder is preferred, such as Zhongli.
Substats
Energy Recharge: Prioritize until requirements are met.