oeh ! oeh ! I get it ! Maybe its a bit of a metafor..
He doesnt want us to see what's under his real mask, just as he doesnt want us -or himself- to see what's under his "mask" ( the mask that bars and hides his emotions ) anymore.
It's a bit of a spoiler, but Irenicus is torn between decisions really. He hates his former self in one hand, but craves the emotions on the other.
He basically hates what he wants to become.
See ? He's emotionally disturbed .. I'd hate to see an emotion-spell get the upper hand of him sometime,.. he'd probably be crying and sharing traumatic events in his life the entire friggin time you try to kill him
