All of the former Hokage have been sealed away in the stomach of the Death God summoning. The Fourth was sealed when he sealed the demon fox inside of Naruto, while the First and Second were sealed when Orochimaru resurrected them and the Third sealed them away, and the Third was sealed when he gave his life to seal Orochimaru's arms.
so the deathgodhas all the hokges soul in there
if naruto does have this technique but it s only 1 of manyand is no the unidentified technique that the 4th wanted him 2 use then iwas thinking whatif h can merge with the death god
ithink itwould b awsome
i don't know ima bored