In fairness to the Doctor, Felix was doing a rather good job of hiding his face at the party, and avoiding the dance floor in particular. At least until things went to Yharnam hell and he got excited trying to organize a summoning circle. He does vaguely remember the musician though. The Doctor has a way of standing out even among performers.

Felix is not yet an expert on Earth costumes, but this fellow's mode of dress seems odd even for them. The holey shirt says a lot, to him. But it's the flicker of energy from the man's hand that draws more of his attention. Another mage, he presumes?

"The intangible ones are more interesting, I think. Chances given and salvation provided, that kind of thing. But sometimes it's informative to see how people react to small debts - I've known men who get quite overexcited about sums of coin that would barely pay for a beer."