What's the best way to level-up character traits & abilities in X-MEN Legends 2, the video game?

Ways to level-up include: choosing increasingly আরো powerful mutant powers & choosing to increase passive abilities (such as bodily defense, firepower, physical strength, & the ability to augment powers of allies).

If আপনি can't answer the question, then how do আপনি level-up your own characters?

JD