Well that will certainly explain something.
He obviously couldn't see the arrow coming because he was too busy
"consulting the elder gods" to notice it.
Although honestly I'm torn because on one hand the dude's a good actor but on the other, it connects a villain I despise in Mustache, to an absolute classic villain in Vamdemon/Myotismon. Ironically a villain that did the
"brutal invading overlord who kills his own men" much better because he only did that when they weren't doing their jobs, turned on him or when he actually needed their energy to complete his evolution.
It was never senseless brutality like when Mustache did it (until 02 anyway).