The 'grossed out' thing is the reason he doesn't display this power often. For the most part, back home, he didn't have to train with it as much as say, Klaus, who had their father hounding him to control his powers. For Ben, his father was just nauseated by his powers and thus didn't have to show them off as much. Only on missions, really. And even then he ended up covered in blood.

At that point, Ben too was nauseated by his own powers.

They were useful now though. He had ripped apart a dozen or so water zombies with some ease. He heard Kirk snarl and glanced back, intending to help if needed, but he looked just in time to see the head fall off a reaching body and drop back into the lake.

Tentacles fished around for a moment more on this side of the boat, then zipped back inside his belly a moment later, staggering him back a bit. He huffed, pulling his shirt down and wagged his arm to the side, shaking some undead muck off into the water. Water that was a mess with body parts.

"All right?" He asked, though he was leaning over to look into the water, frowning. This was gross.