Most memorable Dark Pact moments:
Go! =D

Oh dear, we're opening this line of questioning

Alright. Well once, in our BC game, the group summoned a daemon of Slaanesh, with the intent of making a Pact: 10,000 souls and they all get a Psy Rating of 2, or got their psy rating bumped up by 2 for our actual psyker. Well the psyker disliked out Heretek very deeply, and as soon as the deal was struck, BLAM. Heretek gets doombolted right in the face, and the psyker just says "that's one." My tzeentchian, offended by the psyker's uppity ness, goes "Just as Plaaaaned!" And proceeds to violently stab the psyker and then says "here's two!" Of course, the daemon just stood there with a huge grin.