Nightshade Schemers

Commander is where Nightshade Schemers has any real home, and even there it belongs in dedicated discard shells — Tinybones, Trinket Thief, Nekusar the Mindrazer, or similar commanders that punish or reward emptying opponents' hands. The five-mana entry point means it competes with much higher-impact plays, so it needs a deck that actively rewards each discard trigger, not just one that happens to like hand disruption. In Legacy and Vintage it is legal but entirely outclassed — those formats have access to efficient discard like Thoughtseize and Hymn to Tourach that cost a fraction of the mana. Oathbreaker can support it if the planeswalker and signature spell align with a discard theme, but the bar is the same: the deck has to want the trigger badly enough to pay five for it.