I'd argue that it's more of an icing on a cake to seal the deal. You've already spent some time with both of them, so, clearly you like similar 'hobbies'. And hey, I don't mind the blatant way it (the mansion) was offered to us - after all, that's probably the first REAL piece of power/wealth that we'd gotten. All the Karlssons just give us empty (so far) promises of future power, while Phoebe knows what's up and just gives you something tangible, concrete. And while Celeste has dropped in my ratings (being the stupid cruel bimbo with little brain power), Phoebe soars all the way to S-tier - she's hot, clever and cruel - just how I like them.