Deathbringer, the Two-Headed Blight

Ability

Abyssal Concerto - Requirement: Move 2 Darkness cards from your graveyard to the bottom of your deck. (You can normal summon a unit with Abyssal Concerto.)
■ For the rest of the turn in which this was Abyssal Summoning, it has Defender (at the end of your attack phase, you may move this to your defense zone).

A fell dragon serving under another fell dragon is merely looking for the opportunity to usurp their master's role.