Collei is a Bow User who provides off-field Dendro application and some damage.
Typical Collei Rotation:
Rotation with :
Regarding Weapon Choices:
Polar Star: The best weapon for Collei's personal damage, however it is generally best to opt for a support weapon like as the teamwide buff is more valuable.
Sacrificial Bow: Should only be used at at least [R4].
Regarding Artifact Choices:
Sets
Tenacity of the Millelith (4): Collei's Sprout damage counts as Skill damage, which allows her to be able to keep (4) up during important damage windows. Generally an alternative to (4) or (4) (or if you are already running both in a team).
Gilded Dreams (4): This set is only used in a team where Collei is used to trigger reactions (i.e. Bloom/Burning teams).
Substats
Energy Recharge: Prioritize until requirements are met.