He ran around with a child on the end of his sword as bait to draw in demons so he could slaughter them all. He nearly raped the only person he actually cares about, and regularly acts as though his goals are more important than the lives of every last person on earth.
He is Wrath to Griffith's Pride. He should be one of the Godhand, and even Void and Slan seem to think so. Skullknight seems to be trying to use that to make him a weapon against the Godhand because he is their equal.
Not that I dislike the character, but he is a total bastard. He just keeps trying not to be... and falling short.
What if it turns out that the idea of evil is lying about Griffith being as important as he seems? What if Guts is the one it's really after and everything its doing is to get him right where it wants him? It could either be him or someone else for that matter to boot.