Furious Reprisal

The mandatory split does all the work. You cannot pile four damage onto a single threat: the two-targets clause forces each half to land somewhere different, which turns a mediocre four-for-four burn rate into a spell that answers a specific shape of board rather than any board. It wants two problems that are each worth exactly two damage at once: a pair of small creatures, a creature and the opponent's face to close, two planeswalkers ticked low. Red has a long bench of split-damage removal in this vein, stretching back to designs like Arc Lightning, all of them paying for the second body in raw efficiency. What separates this entry is that each half is free to point at a creature, a planeswalker, or a player independently, so the floor is a flexible reach spell and the ceiling is a clean double kill. The cost is the recurring weakness of every damage-splitter: it thrives against a developed, go-wide battlefield and stalls badly against a single fat threat, where all it can offer is two damage and a shrug.