but i'll, however, die after
come on he won't invincible since he's gonna die at the end
How do you figure that? Do you know what the 8 gates do? Each gate further tears the body from the 1st gate to the 8th. ninjas like SM Naruto, A, and 3rd Raikage has strong bodies with high durability, endurance, and recovery time. The Raikage's lightning armor further increase their endurance and durability, A didn't even flinched when his hand was burning from Amaterasu, the 3rd Raikage (with lightning armor) took on the rasen shuriken which only cancelled out the lightning armor, he fought the 8 tails single hand, fought for 3 days and 3 nights. Naruto in sage mode has increased durability, endurance and recovery time also, falling from on top of a mountain into a bed of spikes without even feeling it. Even when Nagato stabbed Naruto Nagato said Naruto took it on purpose, other times Naruto was stabbed he was in his base. With a strong enough body the 8 gates wouldn't kill them, at most weaken them alot and leave them unable to fight for awhile.