Chao is subpar. I am in the process of giving Chao emblems and I’m finding him a lot more fun to use, but if he wasn’t my only maxed ranger I’d say there’s definitely better choices for them. Before emblems his damage is mediocre, and the mana cut isn’t useful on its own even with emblems. Better if paired with other other yellow mana controllers, with Onatel and Leo they would both be good allies. He’s also the only yellow ranger but unfortunately that color isn’t really good for those quests.
Hu Tao is also subpar, although I like his blindness ailment a lot more. He is good for rush attack tournaments, and he’s also a yellow fighter. Unlike Chao his color is better suited for those quests.