User blog comment:B214/Volume 22 spoilers/@comment-201.215.165.7-20170112030400/@comment-9595671-20170112150619

It's not an infinite lifespan actually, his life force fluctuates between zero and infinity but that doesn't mean he can never die, I think I recall that if it actually did hit zero he'd die which is why he had to learn to control it.

The only thing we can officially say is that when Issei died and then got revived, the years take were taken off from creating the Dividing Gear and then using the Juggernaut Drive were restored because he had been killed.

Except that's an ability only the Evil Dragons have and we still don't fully understand how it works or the limitations it has, either way Great Red and Ophis have never been stated to have that, so we can't say Issei does either as even if they did they gave Issei their power, not their abilities.