I don’t think the part about summoning Death is a reference to anything. After all, we already know what the incarnations of Death are in MOR. And it looks like the conterspell to dismiss Death is lost no more thanks to Harry...
It’s a good thing Harry didn’t follow that line of conversation; if it were me I could picture wondering out loud why nobody had tried the ritual, suddenly breaking off in realization and thereby giving myself away.
I don’t think the part about summoning Death is a reference to anything. After all, we already know what the incarnations of Death are in MOR. And it looks like the conterspell to dismiss Death is lost no more thanks to Harry...
It’s a good thing Harry didn’t follow that line of conversation; if it were me I could picture wondering out loud why nobody had tried the ritual, suddenly breaking off in realization and thereby giving myself away.