me too, other than that, only Satori or Yukari comes too mind
Kind of think no on Yukari just because gentle never seems to be part of her character. Satori does fit but I'm not sure she qualifies as powerful, though her ability is certainly a bit scary. Yuuka really does seem to be a natural fit.
Huh? Hmm...let me think......because I couldn't tell what she was thinking deep down.She was powerful, too...Hmmmm...who could that be...?Everyone ends up that way toward you, don't they, Kogasa!They were all really nice!!I know! I'll ask this for reference: Miss Akyuu, among the youkai you've met so far, which one was the scariest?You've met a lot of folks yourself, Kogasa. Weren't there any scary youkai?I guess there was one time I feared this high youkai that outwardly appeared quiet, beautiful and gentle...