If I block and play Blissful Agony (superior) during the combat
can the acting minion's controller follow up with a Hidden Lurker?
No.
Hidden Lurker can only be played after a combat between the acting
minion and a blocking minion.
The Blissful Agony combat is not such a combat (unless you do a lot of
other card gymnastics in there to make it such a combat, in which case
card text on HL will be met, so HL could be played).
I think the question was more along the lines of:
Can the acting methuselah "interrupt the chain" with Hidden Lurker, and
cause the Blissful Agony combat to fizzle?
Once a Combat has been queued up, you cannot play another card that
queues up another Combat.
--
- Gregory Stuart Pettigrew
Correct.