Even referencing IC history related to the character he's taunting.

Now, I think some of the the things he taunts people about are entirely un-taunt-worthy. But, that too could be role-play, especially if the "goal" is to get under someone's skin and fluster them, and if it's part of his role to be delusional about his own prowess and superiority over others. Given his deity, that sort of role isn't really so unlikely.