Altar of Shadows
Artifact
At the beginning of your first main phase, add 
for each charge counter on this artifact.
, 
: Destroy target creature. Then put a charge counter on this artifact.
Sam Wood
Mirrodin (MRD)
• #143Rulings
You put the counter on Altar of Shadows even if the creature regenerates.
(wotc • 2004-12-01)
The precombat main phase is the first main phase of the turn. All others are postcombat main phases, even if they technically occur before combat.
(wotc • 2004-10-04)
Rulings
You put the counter on Altar of Shadows even if the creature regenerates.
(wotc • 2004-12-01)
The precombat main phase is the first main phase of the turn. All others are postcombat main phases, even if they technically occur before combat.
(wotc • 2004-10-04)