I can actually see Wave surviving until the end. We saw him taking up Ran's ideas of changing and protecting the Empire from the inside. In the anime, Ran tells Wave that once the revolution was over, they (the Jaegers) would be needed to help the new government and keep order, and they are shown to do so in the last episode. I can kind of see Wave ending up in a similar way in the manga, too. This way, he can remain a "good" guy without actually switching sides. Sure, I might be wrong, but it's something I could see happening.
I know I promised to shut up about Ran, but I can't
Sorry.