I need a little help again.
Imagine the following situation: I have Grave Pact, Bloodthrone Vampire and 9 other creatures on the battlefield. The opponent has only one creature on the battlefield but can prevent all combat damage - no chance to deal damage at the moment.
Then I draw Flesh Allergy. Great since the opponent has 11 life left over! I want to cast Flesh Allergy, sacrifice 10 creatures (using Bloodthrone Vampire for the remaining 9 creatures, one is sacked through Flesh Allergy itself) and deal 11 damage to my opponent (my 10 creatures including his 1 equals 11 damage).
~ Question 1: Does my Grave Pact make it impossible to "destroy target creature" (Flesh Allergy) since my opponent would have sacrificed his creatures?
~ Question 2: What if I first cast Flesh Allergy and after the spell has resolved I (as an interrupt so to speak) sacrifice 10 creatures to deal maximum damage? Then the second ability would resolve?
An educated answer would be much appreciated.