Yixuan's Chain Attack is actually meh tier, ~1066% multiplier
Upgrading her weak Chain to Ult is huge because now she has 3 Ults.

If you also have 2nd Stunner Jufufu, that's 900 Decibel refund.

Cute jufufu with phase 3 engine

Are you ready to roll for this almighty tiger? Show me your stash