Board Thread:Off Topic/@comment-25396609-20160502222905/@comment-24534644-20160526193055

I'd assume so, for a limited period of time. Keeping something contained within his own little realm would be constantly draining on his Aura and stamina, so if he does so he'd normally expel them after a short period of time from a different location. Normally the Semblance would be used to bog down opponents as well as avoid (and potentially absorb/redirect) projectile attacks. But if he can put himself in that realm, then yes, he can trap others within it too.

Although it's not necessarily a "Shadow World" in the usual sense. It's really just like a black abyss/void that you're stuck in until you get expelled.