Reading through a copy of White Dwarf (*gasp* people still buy that crap) I couldn't help but notice how similar Omega X (Megaman X series) and the space marine armour look. And then a brain fart aoccoured:

R&D Prof - "X we have a new armour set for you. It will allow you to stop on your enemies with absolutely no affect to your ego"
X - "Awesome when do I try it out"
*dons power armour*
X - "Fear me heretics for your end is near!"
R&D Prof - "... May still need work"

And so was born the most egotistical/powerful space marine ever to invade your living space (^.^)
Standard marine armour is modified with bits and pices from the Megaman X: Command Mission version of the character, though some of it looks like it should have been there from the start :3

Megaman, Command Mission, Omgega X and X are © of Capcom
Space Marines and Lawyers are © Games Workshop
Art ish Mine!