Unit Analysis by Team BethelFrankel
Class
Okay Detonator with some value in 1x1.
Overall
A-
Advantages
+Flexible DPR for both single-tile and multi-tile enemies
+ATK buff is stronger than it looks, especially with her high base stats
Disadvantages
-Competes with Areia, Barton DB, and Lenore for the multi-tile DPR slot, and competes with almost 5 different top tier snipers for the single-tile DPR slot, with Yao being sub optimal in all cases.
-Captain changing gimmick is just that– a gimmick.
-For multi-tile enemies, she is practically identical to Areia, but is entirely worse with worse burst and worse off skill damage due to mediocre chain.
-Loses significant damage on burst turns if in captain slot due to captain change gimmick.
Explanation
Hey, we've almost made it out of the "loses to Areia" section!
Yao closely resembles Areia, but is largely inferior. To make things worse, Yao is a gacha 6* (and not a free 5*) who needs BTs. Furthermore, her only slightly above average damage on single-tile enemies doesn’t make up for her performance against multi-tile enemies, which is mediocre at best. This is particularly detrimental because the primary reason you'd want to bring a detonator is to handle multi-tile enemies, and Forest has an abundance of single-tile monsters (Minos, Mythos, Paloma, Migard, etc.)
Yao is still a functional option for a second detonator, but only if you lack the resources to invest in better snipers and detonators. This is a witheringly small likelihood, given that Areia is free in chapter 3.