Vinny Pazienza shattered his neck in a car accident, literally had his neck fused, almost didn't walk again. Came back to fight RJJ for the 168 crown.
Lack of power and suspect chin are hilariously overrated in how relevant they are. I assume casuals would point these two out. Numerous upper tier boxers in the history of the game had poor power or a bad chin. Lack of footspeed and footwork is way worse.
GTFO Danny Garcia has slow and planted footwork, look where he is, 31-0. It's all about context. Those fighters who had bad chins and **** power, had immaculate defences that was elite. A brawler, or offensive fighter which is what makes up most boxers; if they lack those two abilities, then they are going in the ring disabled. Footwork/footspeed is a skill, it is not a prerequisite to being an elite fighter.
Darrin Morris last fought in July 1999. He died in October 2000, of HIV-related meningitis. During 2001 he twice moved up the WBO rankings, getting to #5 super-middleweight. I'd say that's pretty impressive case of overcoming a disadvantage.
The most impressive one I heard was an old timer abe scrillen.he apparently lost both hands in the butchers shop he worked in,although never a champ,he fought on for a further 12 fights,getting brutally knocked out in each one