Invincible Vol. 2 - Eight Is Enough! TPMark Grayson is just like most everyone else his age, except for the fact that his father is the most powerful superhero on the planet. And now he's begun to inherit his father's powers. In this second volume, the "Invincible Family" finally starts to get a handle on this whole superhero thing, while Mark plans for college and the oft mentioned Guardians of the Globe are finally introduced!