Avengers: Infinity War's Red Skull is game to return to the MCU, whether it's for Doomsday or a potential Captain America spin-off series.

Captain America's closest friend has become his greatest foe in the Ultimate Universe due to the Ultimate Red Skull plot twist ... previously been willing to fight and die for.

The 'Invincible' actor said in an interview that he has pitched a series involving everyone's favorite first Avenger.

What Did Red Skull Ross Marquand Say About His Possible ... He’s also cooking up ideas for a Captain America-centric series that dives deep into the weird and wild corners of the MCU.