Re: PMS Proof ?
I think the reason he doesn't use it is because it still has the drawback of draining a shitload of chakra when it's used. It might not cause blindness, but it would still weaken him considerably. Considering he's stated that he's still weakened from the injuries he sustained while fighting Hashirama, this is actually pretty plausible. He might not have shown it because he hasn't had the need, and it would weaken him more than he already is.