He Can Never Truly Be Yours(rewrite)

**REWRITE**Sirius would do anything for James Potter, he would watch the world burn if it meant that he was happy, but can he handle James' slowly budding relationship with Lily Evans on top of fighting a war? When the unthinkable happens Sirius pushes his knowledge of Magic to another level, just to see his best friend again. AU. (Pairings: SB/JP and JP/LE)