Levy brought a grand total of 18 Mark Graysons to the main ... extremely little screen time. When Oliver Grayson approaches him, thinking he's his brother, Cowl Invincible turns around with ...

Mark's half-brother Oliver Grayson might be young, but he's extremely powerful. Here's how his story plays out in the Invincible comics.

While Mark is still on Earth, his dad, Nolan Grayson, and Allen the Alien are ... are higher than ever due to Nolan allowing his younger brother, Oliver, to travel with them to space.