Rocket Racoon: If a character is dealt damage by Overkill, is that damage dealt by the source of the original attack? And…

Question

If a character is dealt damage by Overkill, is that damage dealt by the source of the original attack? And if not, what is that damage dealt by? For example: Rocket Raccoon plays Relentless Assault (with Overkill) targeting a 1 HP minion, when the Villain is also at 1 HP. Overkill deals excess damage to the villain. Does Rocket draw a total of 1 card or 2?

Answer