User blog comment:Umbralis/Nasus - Benevolent or malevolent?/@comment-6301771-20131201051813/@comment-5331854-20131202094237

A few are canon, though. The best example is Pentakill, which has been mentioned in a JoJ iirc. They're like the Runeterraen equivalent of Azeroths "Level 90 Elite Tauren Chieftain".

Still, there's no hint that Infernal Nasus is a thing.