Mohawk isn't underpowered -- she just doesn't have enough health compared to equivalent options, so she's a less desirable choice in team building. Bump her health up by, say, 20%, and she might be as popular as her little sister.
Soooo weak. For a "goddess", she should have more health.
There are certain not-good but not-terrible characters they push over and over, almost like they want us to believe they are good. DD seems to get that treatment lately also.
I think most see her as underpowered because they're using her mainly for black into attack tiles. She's still one of the strongest AP generators for green, and the cascades caused by green/yellow. I have yellow maxed instead of black, because she's the strongest characters in infinite team combos. That's much more useful to me in PVE than more attack tile damage.
Mohawk Storm in the comics WAS NOT the "goddess" that she once was. She was actually DEPOWERED when she was sporting that look.
Maybe that's why they chose to make her on the weak side? Still sucks, though.