User blog comment:JediSpectre117/Regarding the surviving Prothean./@comment-58609-20120220010348/@comment-3186471-20120221002001

Mordin is also a scientist but he's still deadly -- in a time when his species is going extinct, he probably had no choice but to learn to fight. Also, there's places on the Citadel where noone has been able to go except the Keepers. Who knows, maybe he found a way to access one of those areas.