Ollanius Pius
The most hardcore Guardsman ever to walk the earth. Ollanius Pius put himself directly in front a walking god of battle in the hopes of protecting the Emperor of Mankind. The fact that he did so without fainting, shitting himself in terror, or mewling like a wounded grox suggests that his testicles must have been forged from Mars-grade Adamantium. His death proved that Horus had given himself over to chaos completely; and with this in mind, allowed the Emperor to lay down a righteous psychic asskicking strong enough to rend his former son from existence.
Naturally, like so much other awesome shit, Games Workshop has retconned him out of existence (first replacing him with a Space Marine, and then an Adeptus Custodes) which is SIX KINDS OF LAME. FUCK YOUR CONTINUITY, GW.
(this is not official content)