Hey - what's this zeta on 5's all about? Kix inc?

Even though Old Ben has that — there are several reasons not to add it to Fives:

1. Game balance. It’s a very powerful unique and having fives revive after giving his stats for the first time only can still be OP
2. It’s not thematic — the Ability is based on Fives sacrificing himself for his brothers. It cheapens his sacrifice if he’s able to come back afterwards