I'm fairly certain that I know how this works, but I figured that I would post this just to be sure.
I have a Memory Erosion in play, and my opponent plays a spell. When I play Lapse of Certainty to counter his spell, does this mean that his spell card will be among the two cards "milled" by Memory Erosion?
I consider this based on the assumption that the sequence of events goes as follows:
(Memory Erosion is in play under my control.)
. Opponent plays a spell.
. Memory Erosion triggers, and its ability goes on the stack.
. I play Lapse of Certainty targeting my opponent's spell. Lapse of Certainty goes on the stack on top of Memory Erosion's ability.
. Lapse of Certainty resolves, countering the spell and putting its card on top of my opponent's library.
. Memory Erosion's ability resolves, putting the top two cards of my opponent's library into his graveyard (including the countered spell).
this works like you say. alternatively if you do want his spell to back on top of his library you can wait for the memory lapse ability to resolve, putting the top two cards of his library into his graveyard, then use memory lapse to counter his spell and put it on top of his library.
I have a Memory Erosion in play, and my opponent plays a spell. When I play Lapse of Certainty to counter his spell, does this mean that his spell card will be among the two cards "milled" by Memory Erosion?
I consider this based on the assumption that the sequence of events goes as follows:
(Memory Erosion is in play under my control.)
. Opponent plays a spell.
. Memory Erosion triggers, and its ability goes on the stack.
. I play Lapse of Certainty targeting my opponent's spell. Lapse of Certainty goes on the stack on top of Memory Erosion's ability.
. Lapse of Certainty resolves, countering the spell and putting its card on top of my opponent's library.
. Memory Erosion's ability resolves, putting the top two cards of my opponent's library into his graveyard (including the countered spell).