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.
Legalities
Legal
Duel
Penny
Predh
Legacy
Modern
Vintage
Commander
Oathbreaker
Not Legal
Brawl
Future
Pauper
Alchemy
Pioneer
Explorer
Historic
Standard
Timeless
Gladiator
Oldschool
Premodern
Standardbrawl
Paupercommander
Rulings
2004-12-01
You put the counter on Altar of Shadows even if the creature regenerates.