User blog comment:Miskos3/Fairy Tail 521: The Strongest Wizard, Review/@comment-5894890-20170212010455/@comment-1776824-20170214201426

More Magic Power means you can put more strength behind your attacks, fight longer, fight harder, and fight smarter. It's slightly different from mana, but it's not a complete boost either. It just gives them more "oomph," to put it simply.