Pure Ownage is two words that form into one, Pwnage.
The P from Pure is taken and it replace the O from Ownage as it creates a better word than Ownage, Pwnage.
The short saying of Pwnage is Pwn, same as Ownage and Own
PC player 1: I am ownage!
PC player 2: well i am pwnage
PC player 1: pwnage?
PC player 2: yeah a word that own you more