All this eye scars talk actually reminded me of Auron from FF10, which I've been replaying. I feel he's pretty similar to Zoro. Specifically an EOS Zoro who has completed his journey with Luffy and become the WSS.
Auron is stoic and reserved, but imparts lots of helpful wisdom to the brash Tidus. Zoro feels like he's getting more wise and weathered, especially after training with Mihawk. Auron also embarked on a great journey with Braska, similar to how Zoro's currently on a great journey with Luffy. The experience that came from that journey is reflected on Auron, as I think it would be for Zoro once he's finished his.
There are some differences, like Auron not being directionally challenged, and Zoro being a bit less distant, but when I envision a mentor Zoro, Auron's the closest thing I can think of.