Level 5 Shield Boomerang damage calculation

[kysp]

I think he's onto something, if it's skill damage increase I don't see why you'd only multiply the atk part.

Because there's a comment in the code: "Refine bonus applies after
cards and elements". I think the same applies for weight bonus. And the description of CS says "Increase damage of ..., and Shield Boomerang by 30%". So you multiply the damage given.