[Vicky82]

When Rahzar died in Requiem some people including me thought he wasn't dead because we didn't see his body but then he returned to his undead body by Kavaxas

To me Rahzar last appearance was closure for me because he wasn't alive after all, just undead like Shredder and he fell into the Netherworld so we know he aint returning.

Fishface last appearance was also closure for me because he left the foot clan and gone back to old life as a thief.

To me Tiger Claws last appearance didn't feel closure at all because his truce with the turtles was done off screen and it felt like he was going to return later but it turned out it was his last appearance.

So to me Fishface and Rahzar's last appearance were closures.

If Rahzar wasn't seen again after Requiem, I wouldn't have considered his last appearance as closure because we never saw his dead body after he drowned by Letherhead.