Brion Markov is more than a superhero, as he’s also the Prince of Markovia. A founding member and funder of Batman’s shadow team The Outsiders, Geo-Force has gravity and earth manipulation abilities. Like his half-sister Terra, he can shoot and manipulate rocks around him to take down foes.
Upon his first un-official mission with the Justice League, Deathstroke tries to blackmail him in the same way he blackmailed Terra, but Brion isn’t willing to play these games. He informs the rest of the Justice League and monitors Deathstroke as Lex Luthor develops a brand new iteration of the Injustice League. Unfortunately, the hero ends up getting tortured after being found out, but he sticks around with the team and proves his mettle time-and-time again.