Grim Lavamancer question

[KobeBryan]

Opponent has 2 cards in the graveyard. I have a faerie macrebe in hand. He has 1 grim lavamancer in play.

He activates grim lavamancer to shoot me for 2 life. I use my faerie macrebe to remove his two cards. Can he still shoot me with the grim lavamancer?

[miko]

Removing the cards is part of the activation cost of the ability. It's like paying the mana cost. You cannot react to it by destroying the land - so you cannot remove the cards in response to activation.

[Skeggi]

Situation:
Player 1 has a Grim Lavamancer without summoning sickness (is this still a term?), has an untapped Mountain and two cards in his graveyard.
Player 2 has a Faerie Macabre in his hand and a Stoneforge Mystic on the battlefield.

The play:
Player 1 has priority. He declares he wants to use Grim Lavamancer's ability on Player 2's Stoneforge Mystic. He then proceeds to pay the costs: he taps his Mountain for a red mana, taps his Grim Lavamancer and exiles the two cards in his graveyard. Game-technical, this is all done at the same time. Player 1 has now placed Grim Lavamancer's ability on the stack, wants it to resolve, so he passes priority.

Player 2 now has priority. He sits with a targetted Stoneforge Mystic on the battlefield and a Faerie Macabre in his hand. He can use Faerie Macabre ability to exile 0 cards from Player 1's graveyard since they're already gone. Player 2 has no choice but let the ability resolve and let Stoneforge Mystic receive 2 damage. Player 2 passes priority and Stoneforge Mystic is placed in Player 2's graveyard as a result of a state based effect.