I raise you Bermaine Stiverne When you beat him you had ascended the mountain in the eyes of some. So he must have been pretty special King maker to Deontay Wilder and Trevor Bryan, and to a lesser extent, Joe Joyce.
Yeah I might vote for him. He got the title in impressive fashion anyway. Second others who said Castaño did defend his real title against Charlo. Typically a draw is considered a successful defense.
He was bigger than Hagler despite moving up from 154 and far too big for any light middle in the mid 80`s, he was thumbed in the eye by Thomas and then got sparked by the awesome Norris a few years later, he also got sparked by G-man who was a killer, Mugabi was not a smart fighter and when Norris flawed him he tried to fight back while hurt which was suicide.