Lich's Tomb annihilator attack lose life magic sac permanents

[peanutbutter]

I have Lich's Tomb out

I get attacked with Pathrazer of Ulamog and I dont block it

do I have to sacrifice 9 or 12 permanents? (because am thinking maybe I combine three permanents from annihialtor and tomb)?

[Arix]

12. Annihilator triggers when the creature attacks, before blockers are declared, and long before damage is dealt. So you sacrifice three to annihilator, then a few steps later, you take 9 damage and have to sacrifice another nine permanents.