Heavy armor wasn't suited to those whose entire fighting style revolved around lightning speed; anything of the sort made throwing blades just that little bit slower, and the added protection would only leave cracks elsewhere in one's defense. Besides, armor was for people who couldn't make healing potions from bottled water. Or regenerate, in Ardyn's case.

...Frankly, he was more worried about damaging his sweater than himself. Fashion crime or not, he found it all comfortable.

"You've nothing to worry about. I can more than hold my own if need be, and if I'm wrong then it isn't as though I'll be killed."