@SnazzyChri21985 Madra gave Nagato the ability in order to fulfill his plan. Madras likely told him that toninglate his ego and to set him down the path that Madara created in order to bring him back to life.
@pooflikemagic44@Animeeverse_ I had to rewatch the scene Tobirama says that they are βnearlyβ their full strength. So it was much more refined compared to the Naruto series but it still didn't bring them back with their complete strength.
@Coruptify_@Animeeverse_ if I remember correctly, hashirama wasnβt even at his full power because Orochimoro was worried to be difficult to control him.