Storage Cloning
cloning: clone a mostly closed container like a room or bag and its contents yet they'll overlap each other. The user can choose who or what enters which room. Could have a bag with 7 cakes and 1 bear trap, each occupying the entire bag. Can split a container to up to 8.
cloned contents: objects and people inside get cloned in the process, but upon taking too much damage (the more copies the less damage required), merge with all instances in other rooms. They also merge if either tries to leave and the user may will a room's contents into merging, but can only be split while the container is splitting.
room merge: willed by the user, when the room takes too much damage or when the user gets too far from any of its walls (this also limits the maximum size of a container). During this, all split items and people merge, but new people/objects might end up appearing on each other, which while not nuclear, can be devastating.
appearance: while inside one can't tell that anything is different. From outside each thing that isn't in the same place in every room will look fuzzy, which is usually the case for placed objects/people, meanwhile cloned things due to occupying the same place in every room will look solid from every perspective until moved.
suppression: a cloned telekinesis user will be less able to exert influence outside the room, but influence on cloned or new things will remain the same, thus technically 1 (cloned) fighter can fight 8 (new/guests) at once