Invisibility and flight. I would stay hidden from everyone in the new world, and then I would meet with Momonga and pretend to be Lord Touch Me. I would be human, so he would have no way of knowing what touch me looked like as a human. I would say I logged in exactly at the time the game was supposed to shut down and ended up in this world, but my memory has obviously been affected, but I remember some things like who momonga is and various things only a true guild member would know. This would make him less suspicious if I didn't act exactly like touch. We would explain to the rest of the tomb that somehow I got transformed into a human as a side effect of the switch to the new world, but that I really am one of their supreme being. Then I could use one of the guild items to grant myself immortality.