|Appeared in||Batman Beyond: The Call|
Rex Stewart is the son of John Stewart and Shayera Hol. He has inherited his mother's powers and becomes Warhawk.
Warhawk was a very stern and valiant warrior who had a slightly impulsive temperament. When the JLU was suspected of having a traitor among its ranks, Warhawk wasn't at all amenable to Batman's inclusion in the team, after Superman recruited him without their consent. Warhawk immediately spurned Batman and dismissed him as a punk. Even after saving Aquagirl's life, Warhawk reprimanded Batman for not calling him and Big Barda on the intercoms.
During a rescue mission, Warhawk got an emergency call on the JLU frequency. However, upon realizing Batman didn't get that call, Warhawk became suspicious. He told Batman to stay behind, and headed off to deflect an incoming warhead. He activated his body covering armor, and then shed it and fled to safety. He operated the armor remotely, and when Superman (Starro) detonated the missile, Warhawk appeared to be killed.
A few hours later, Warhawk returned to the Metro Tower, when Batman was revealing to the JLU the real culprit behind the sabotages and attacks. His return was greeted with great relief by his teammates. He explained how he had eluded death and what had prompted the deception. Warhawk's opinion of Batman started to change, as he actually praised him for disobeying his previous command to stay behind. Although Warhawk set off to take revenge on Superman, he was held back by his teammates who wanted to give Superman the benefit of the doubt. However, when Starro was forced to surface, a battle between Superman and the League ensued.
After the whole ordeal, Warhawk admitted to being wrong about Batman.
In the alternate future created by Chronos, Warhawk, an aged Static, Batman and the old Bruce Wayne, were the only surviving JLU members. After both the Metro Tower and the Batcave had been destroyed, the remaining JLU used an abandoned high school as their headquarters. Later on, the JLU saved the modern-day Justice League (John Stewart, Batman, and Wonder Woman) from Chronos's enhanced Jokerz. Afterwards, Warhawk introduced himself as Rex Stewart, the son of John Stewart and Shayera Hol. As soon as the Justice League and JLU found Chronos, they engaged his Jokerz in another fight. All of these events were erased when John and Batman reversed Chronos's effect in the timestream.
- Super strength
- Superman - Leader
- Bruce Wayne - Leader
- Batman - Teammate
- Aquagirl - Friend and teammate
- John Stewart - Father
- Green Lantern - Teammate
- Hawkgirl - Mother
- Big Barda - Teammate
- Starro - Enemy