He can’t respawn from what I remember. I think the 7 days thing was basically “you can only spawn a new one in this slot after 7 days” but since he had a third slot ready, he spawned Heinz II. I think the slot for the first Heinz was repurposed for the merc king avatar.
From what I remember, I think once an avatar dies, they are fully reset, including their beginning ability. So the durability ability was completely gone after he died. Heinz I is gone, but the slot was open for Harley

Why are we missing one?
1 The skeleton
2 Vampire
3 ????
4 Saint
5 Big Guy
6 Appraiser
7 Elf
Where is guy #3????