Trolls, unlike Huldra, do in fact sleep.
They're also weak willed.
And dumb as mud.
The monster nods a few times before slumping forward in a catatonic stupor.
How often does that ability actually work?
Freddie raises an eyebrow at the sleep attack! "Well. That's useful. Why didn't you ever us that one on me?"
That's a dumb question Freddie! You just don't sleep anymore.