User blog comment:Miskos3/Fairy Tail Chapter 505: Trump Card, Review/@comment-4449950-20161007232427/@comment-7418318-20161008075507

The whole Makarov situation could have been vastly improved by incorporating two lines and one drawing into the mix.

When Mavis says she has a plan, Makarov could have asked "Can your plan guarantee that none of my children will die?" to which Mavis doesn't say anything, but turns slightly away from his gaze in sadness and shame. "Then I won't stop."

Like this it makes sense. He sacrifices his life to save lives, not to prevent some minor injuries. And Mavis accepts his choice of actions because she knows his sacrifice will ultimately save more lives than it costs. One life for several.