AN: This has bounced back and forth between being an original work and a fanfic. The only reason it's still a fanfic is because I wanted to use Saber and Archer. I hope you enjoy it.
Angra Mainyu was bored. The Fifth Holy Grail War was coming up and the Servants set up to be summoned were just so… standard. Archer was an anomaly, sure, but he was just one Servant. Plus he was after revenge… against himself. Okay, so Archer was pretty badass, but still. There had to be some way to spice things up. Why not pull in some random bystanders? Yeah, and have more than seven Servants too!
Wait, that had been done. Alternative Servants? Done. Fictional character Servants? Seen it. But what about Servants from other universes that weren't fictional characters. In the infinite multiverse, there was an infinite pool of Heroic Spirits to choose from. And he could still have more than seven of them.
His decision made, Angra Mainyu set about selecting the Servants.