Mind games (??)

So I was watching the avengers:age of ultron last night and the character Scarlet gave me an idea for a story-mind games- because she can control people's mind (make them see their fear or look in their minds).
I wanted to base a character of Scarlet, me character-crystal:
can read minds
Get into people's head
Her eyes change colour whenever she uses her power
She can make anything into crystals and jems

Please tell me what you think in the comments whether it's a good/bad idea and whether I should do or not.