Board Thread:Warhammer 40k General Discussion/@comment-14745711-20130906234048/@comment-25177957-20140907200123

All or most of the Primarchs' special abilities came from the Emperor since they were created through his genes, and being a perpetual is too powerful an ability for it to not have come from the Emperor. Why the Emperor can't or hasen't repaired himself could be because he let down his guard when fighting Horus.And now that he's interned in the Golden Throne, and forced to fight the Chaos gods in the warp and protect mankind, he hasen't the sufficient psychic energy to repair himself. But if somehow a powerful psyker brought him back, then he'd easily be able to repair his bodily wounds.