Cemetery Gatekeeper

The enters-the-battlefield exile is a read on the game to come: you pull one card out of a graveyard, and its card types become a two-damage tripwire every time anyone plays a land or casts a spell that shares one of them. Grab a land and every fetch, every tapland, every land drop turns into a burn trigger; grab an instant against a control shell and their own interaction starts biting them. The choice sharpens because the check runs on shared types rather than a named category you announce: exile an artifact creature and you tax artifacts and creatures at once. The trigger is fully symmetrical, reading "whenever a player plays a land or casts a spell," so you pay the same tax when you play into the taxed type. That is why exiling a land is at once the most punishing and the most dangerous read: nobody stops playing lands, least of all you. Reframing a pinger as a repeating tax, and firing on lands as well as spells, is the wrinkle that lifts this above the usual cast-a-spell burn creature; first strike keeps the 2/1 relevant in combat while the tax runs quietly in the background. The catch is a single selection with no reroll: a bad read leaves a first striker with an inert ability, and a greedy one aims the damage back at its own caster.