Slayer of the Wicked

This is a Nekrataal aimed at a specific bestiary: a four-mana 3/2 whose enters-the-battlefield trigger reaches for exactly three creature types and nothing else. The narrowing is the whole point. Most enter-the-battlefield removal creatures in white care about color or about being a creature at all; this one cares about Vampires, Werewolves, and Zombies specifically, which means its value swings violently with what is sitting across the table. Point it at a board of monsters and you have spot removal stapled to a body, a permanent that can be flickered, bounced, or reanimated to fire the destroy trigger again. Point it anywhere those three tribes are absent and the trigger simply has no legal target: it never goes on the stack, and you are left with a 3/2 for four that does the work of a vanilla soldier. The "you may" is not insurance against bricking, it is courtesy. When you are the only player controlling a legal target, the optional wording is what keeps you from being forced to blow up your own creature. That is the entire design negotiation: a clean, reusable answer to a defined slice of the monster world, paying for that reusability with a body that earns its mana only when the format obliges by fielding the right horrors.