Lobotomist + Portent or Memory Lapse

[AceofAllan]

Alright, I've been trying to cook up a deck to abuse Circu, Dimir Lobotomist, but I need to know how he interacts with some cards, specifically Ponder and Memory Lapse.

Circu, Dimir Lobotomist
:2: :u: :b:
Whenever you play a blue spell, remove the top card of target library from the game.
Whenever you play a black spell, remove the top card of target library from the game.
Your opponents can't play nonland cards with the same name as a card removed from the game with Circu, Dimir Lobotomist.
2/3

Q1: I play portent, targeting my opponent's library, to look at the top three cards. The ability triggers when I play the spell, but will the ability happen before or after I've re-arranged his cards?

Q2: I counter a spell with memory lapse, does it go on top of my opponent's library before or after the Lobotomist has removed a card?

Thanks in advance.

[Nihil Credo]

Whenever you play

The ability triggers when the spell is played, go on the stack above the spell itself, and resolve before the spell does.

[KillemallCFH]

In both cases, Circu's ability resolves before Portent/Memory Lapse resolves, no Memory Lapse cannot be used as a hard counter like you hoped.