I see in jinyong universe had several handicap Martial artists either lost an arm, cripples, blind, turn insane and etc. Some are average, some are powerful. I just list some down but havent them yet by power.
Note: Though Hong Qigong lost one finger but i dont see him as handicap. The handicap factor should cause much inconvienence, discrimination or major discomfort in that character's life.
Not in ranking.
(maybe someone can add more and thenrank them from powerful to weakest)
Wuyazi - crippled
Duan Yanqing - crippled
Murong Fu - insane (in the end)
Ouyang Feng - insane (ROCH version)
Mei Chaofeng - blind
Ke ZhenE - blind
Qu Lingfeng - crippled
Feng Mofeng - half crippled
Lu Chengfeng - crippled
Xie Xun - blind
Hai Dafu - blind
Dongfangbubai - castrated
Yue Buqun - castrated
Lin PingZhi - castrated
Lin Yuantu - castrated
Mu Gaofeng - hunchback
Zuo Lengcan - blind
Yang Guo - lost one arm
Qiu QianChi - crippled
Gongsun Zhi - lost one eye
Shi Wanchen - partial blindness
Jiunan - lost one arm
One of the 3 elder monk in HSDS - lost one eye