Rule 418.6.b

If a game effect does specify a source, then that source is what is considered the origin of the Damage for this Deal action.

• 418.6.b.1 Units and Spells can be the source of Damage for Deal actions.
• 418.6.b.2 Abilities can be the source of Damage for Deal actions.
• 418.6.b.3 When a spell or ability specifies a Unit as the source of the Damage for the Deal action, it is not in addition to the…
• 418.6.b.4 The controller of the source of a Deal action is responsible for that Deal action unless the player performing the…

Rulings that cite this rule

• What counts as “spell and ability damage?” What does this card do?
• So… What does this card do?

Official Core Rules