Unholy Heat

Unholy Heat deals 2 damage to target creature or planeswalker.
Delirium — Unholy Heat deals 6 damage instead if there are four or more card types among cards in your graveyard.

Special Guests

Mystery Booster 2

Modern Horizons 2 Timeshifts

Outlaws of Thunder Junction Commander

Secret Lair Showdown

The card types that can appear in a graveyard are artifact, battle, creature, enchantment, instant, kindred, land, planeswalker, and sorcery. Legendary, basic, and snow are supertypes, not card types; Kavu and Equipment are subtypes, not card types.

Unholy Heat checks your graveyard as it resolves to determine if it deals 2 or 6 damage. At that time, Unholy Heat isn't in the graveyard yet.