So far 3 SHs (2 from Weakling trio) have taken at least 1 Ulti headbutt. Luffy ate it like lunch & could take way more, Usopp looks like a 3rd will be his limit, & Nami said a 2nd headbutt would kill her & I believe her. But how would the rest of the SHs do?
Here's how I see it;
Luffy: Infinity
Zoro/Sanji/Jinbe: 100's
Franky: Baker's dozen
Chopper: 6
Brook: 5
Usopp: 3
Robin: 2
Nami: 1
Here's how I see it;
Luffy: Infinity
Zoro/Sanji/Jinbe: 100's
Franky: Baker's dozen
Chopper: 6
Brook: 5
Usopp: 3
Robin: 2
Nami: 1