If you ask Tobirama if he has any regrets, it would probably be: I spent the first half of my life getting to know you, and the second half of my life remembering you, and spending my whole life discovering that I fell in love with you, and missing you in the Pure Land - Senju Tobirama
Shizhan Tobirama, who was reincarnated by the filthy soil, listened to the Hagoromo family's two or three stories. When he returned to the pure land, a strange time and space band occurred. When he opened his eyes, he found that he had returned to his childhood. Senju Buddhama and Uchiha Tajima were both still alive. His stupid elder brother had not yet met Madara, and Izuna, the person he missed until his death, was still safely staying at the Uchiha station.
Purpose: Peace