S1·E13 The Denizen of Warped Dreams

Oz and Gilbert arrive in Cheshire's dimension and are attacked by Cheshire, only to be temporarily rescued by Sharon's chain, Eques. As they try to escape from Cheshire, he catches up with them, slashes Gil(who falls off the stair railings) and attacks Oz. Cheshire tells Oz that Alice purposely tore up her memories of her own free will and that this dimension is made by Alice's memories. Cheshire also reveals his duty of protecting Alice's memories so that no one can find them. Gil later regains consciousness in a garden and encounters the man in Alice's memories, whom Gil mistakes for Oz as they both have blond hair and emerald green eyes. The man reveals his name to be Jack Vessalius.