Dark Depths

Set
Coldsnap
Rarity
Rare
Text
Dark Depths enters the battlefield with ten ice counters on it. : Remove an ice counter from Dark Depths. When Dark Depths has no ice counters on it, sacrifice it. If you do, create Marit Lage, a legendary 20/20 black Avatar creature token with flying and indestructible.
Legality
Legal in: Commander, Duel, Legacy, Vintage
Banned in: Modern
Rulings
2018-12-07: Dark Depths really is a land with no mana ability. It doesn’t tap for colorless mana.

2018-12-07: The last ability of Dark Depths is a state trigger. It won’t trigger again while the ability is on the stack, but if the ability is countered and Dark Depths is still on the battlefield with no ice counters on it, it will trigger again immediately.

2018-12-07: If Dark Depths leaves the battlefield before its triggered ability resolves, you won’t be able to sacrifice it, so you won’t create Marit Lage.