Every Genshin Impact player has characters that they personally really like, even if they're less popular. For me, its definitely Sayu. Sayu is a precious bean who is perfect. With someone so good, you can probably solo Genshin with only them, and for Sayu, that has to be true.
Rules:
I can only use Sayu in battle.
Any puzzles that require another element can be completed with another character.
No fighting in co-op.
All claymores are allowed
Inspired by @mistahfeet