I don't really know a whole lot about how Singularities work, but I'm pretty sure this isn't one. One of the people here is a Master from a Holy Grail War I was part of.

[She's also the one he ended up contracting with, so that's not necessarily a bad thing, but Singularities are more about summoning Servants, not summoning Masters.]

...Well, there's that, and I've been here for what feels like months.