and in undertale its apparent that monster could absorb human souls and it would make them gods so it also could mean with that power he used it to escape and kill everyone
i know im looking as the basement could represent the void and it is a different universe but if my theory is true then it could be possible that gaster absorbs your soul
wait the update almost certainly proves its gaster morshu refers to the man as the man who speaks in hands or thats what the dialog you say to him says which is the exact same name one of the undertale secrets referd to him as so i think it means its gaster
welp i was closer then a normal guy itsvconfirmed that the man is a combo of gaster and rick astly so his name is rick gastly so my theory is half right
