Oh, there's my girl. ♥ Illyana for the win, dude.

1) The biggest reason is because she's a ruler of hell and has a badass temper. I'd be terrified of demons being flung at me in an argument.

2) She's always running around with the X-men to far off parts of the globe, and I would be left behind and lonely.

3) She's practically soulless, which means she'll think any end is worth the means, and that's too mercenary for me.