So when an indestructible creature gets to zero toughness via negative counters it is placed in the graveyard
Even though I love the art, this is one Lair I will be avoiding
Dark Confidant has also been a long time Plan B for combo decks, whether in the sideboard or the maindeck, such as Paulo Vitor Dama Da Rosas Dark Depths deck from Pro Tour Austin: Creatures (11) Lands (24) Spells (25) Dark Confidant is great for finding combo pieces and great when you dont assemble the combo
Its effect often ends up being very similar to Thalia, Guardian of Thraben and reactive decks playing Instants/Sorceries are faced with a hard choice
Those are rare circumstances, and the reigns of those decks end very quickly
During Throne of Eldraines time in Standard, everyone anticipated the Embercleave, and would try and keep removal or other interaction open for when it inevitably dropped