[Puddingman]

Yea, I agree with prehemencie's idea, it's pretty much proven:

Spoiler for Soul Eater Ending:

When Maka punched Asura she was using her Anti-Magic power that Stein and some others were referring to. It's the same thing that restored Crona (physical contact), and I believe she used it one other time in the series. Her courage is what allowed her to physically get that close to Asura, then she made physical contact with him via punch to use her anti-magic. When she punches, it's clear that something goes through Asura, the way his face fluctuates like it's swallowing something.