You'll slip up, and when you do.
He has a snappy sense of humor but loses his temper quite easily due to impatience.
But you can call me your new lord and master for all of eternity! In the present, when he learns of Bill's plan to invade the mainstream dimension, he destroys the teleporter, but at the cost of a dimensional rift leaking out of it, which he contains.
Oh, even when you're about to die, you Pines twins can't get along.