Not too good at this, but I might as well give it a shot.
Amiya's usual moves are, well, magic blasts, barriers for protection and possibly swordsmanship if an opponent gets up close or if she gets up-close. IIRC, she doesn't typically mind-hax a person to death, even if she could do it, due to being OOC for her unless a situation really, really needs it (and probs won't be too useful as Tasha has mind manip resist).
She might try to "read" Tasha's past via Retrocognition and could "copy" his skills as a side-effect like what had with Ch'en in canon-however, Tasha uses guns. Amiya doesn't. So she likely won't benefit too much from it unless she conjures up a gun herself.
Looking at Tasha's profile, tho, even if I am too well-versed in his verse, he does have a large range advantage over Amiya and they aren't too far apart in stats (with Amiya only being 1.57x stronger), so I can foresee Tasha wearing Amiya down with ranged attacks, at the very least
And that's all I got. Tell me anything I am missing.