In terms of performance Cactus is really really strong.
A-Tier is definetely appropriate (A+).
I snagged her myself a few days ago (Rainbow Coins).
But there is one factor i don't like about her:
Her voice is horrible in my opinion. She speaks like she is in delirium or something
They want to change a few VA in the next couple of patches. Cactus VA gets swapped out.
I don't know how good the next VA will be.
So be warned if you value a good Voice!!!
Cactus ORA ORA ORA Onslaugt is flames though