My Prince is the 2nd episode of Justice League: Knights of Rao.
- Supergirl / Kara Zor-El / Kara Kent (first appearance)
- Geo-Force / Brion Markov (first appearance as Geo-Force) (joins the Justice League)
- Justice League
- Batman / Bruce Wayne
- Batgirl / Barbara Gordon (first appearance)
- Robin / Damian Wayne (first appearance)
- Black Canary / Dinah Lance (first appearance)
- Green Arrow / Oliver "Ollie" Queen (first appearance)
- Green Lantern Corps
- Guy Gardner (first appearance)
- John Stewart (first appearance)
- Kyle Rayner (first appearance) (joins the Justice League)
- Stargirl / Courtney Whitmore (first appearance)
- Swamp Thing / Dr Alec Holland (first appearance) (joins team)
- Batman / Bruce Wayne
- Warlord / Travis Morgan (first appearance)
- Deimos (single appearance) (dies)
- Silver Banshee (first appearance)
- Dark Archer / Malcolm Merlyn (first appearance)
- Lobo (first appearance)
- Lex Luthor (mentioned only)
- Maxima (mentioned only)
In order to overcome grief over her cousin's disappearance, Supergirl goes with her friends on a mission to stop the dark sorcerer Deimos and his spawns from destroying Warlord's village. During her mission, Supergirl progressively forms a new relationship with Geo-Force, who is also determined to keep her safe as a genuine retribution on Superman for saving his young sister Tara.
It all starts in a dark tower near the village of Skartaris, where the mad sorcerer Deimos is witnessing new weapons forged by his minions with help from the Dark Archer and Silver Banshee, hoping that they will help conquer Skartaris and destroy his old foe Travis Morgan, the Warlord. Little does he know that he is being spied on by two heroes who are determined to stop his madness: one contacts Brion Markov via Geokinetic telepathy, the other contacts the Justice League for help.
Meanwhile, in Metropolis, Supergirl is resuming her superhero work while once again with people cheering on her. Though pleased to feel trusted by everyone, Kara is still saddened over the fact that her cousin had to leave Earth after what happened in the National Congress. She is eventually approached and comforted by her friends Barbara Gordon and Courtney Whitmore, who assure her that people know it was not his or any of the heroes' fault and only choose to blame the authorities who did not clear their names in time, especially Lex Luthor. Sometime later, Supergirl has moment alone until she is confronted and chased by the Czarnian bounty hunter Lobo, who was hired by the Almeracian Queen Maxima to capture Kara to lure Superman to her. Just then, Lobo is thwarted and repelled by Brion Markov (in his superhero alter-ego of Geo-Force), who singlehandedly repels him back to Space and is quick to win Kara's gratitude (and also secret crush). Just then, both Supergirl and Geo-Force are called respectively by the Justice League (who has answered to a distress call from Kyle Rayner to his fellow Green Lanterns John Stewart and Guy Gardner) and Swamp Thing (who demands Geo-Force's help to protect the Green).
The Justice League (Supergirl, Batman, Batgirl, Robin, Black Canary, Green Arrow, Stargirl and Green Lanterns John Stewart and Guy Gardner) arrives in Skartaris, where they battle hordes of creatures surrounding villagers under Warlord's protection while searching for Rayner's signal. Meanwhile, Geo-Force and Swamp Thing meet in a shadowed swamp and discuss an strategy to stop Deimos' insanity until they encounter Rayner, who agrees to cooperate with them. Plus, Geo-Force learns that the Justice League is near and Supergirl is with them. While Stewart discusses strategy with Warlord and the others help forge better weapons, Supergirl goes on to find Rayner. To her surprise and pleasure, she meets for the second time with Geo-Force, who introduces her to Swamp Thing, who had called Brion to help stop Deimos from poisoning plantlife with his creations. The two go with Rayner to regroup with the League, but Swamp Thing stays because of Warlord's mistrust in him. The Justice League and Warlord's troopers are confronted by Deimos and his army aided by Silver Banshee and Dark Archer, declaring this his and Warlord's final battle.
As the battle begins, Geo-Force volunteers on taking on Deimos, who, despite his powers, is vulnerable to the elements of Earth. Just as he shares with her the same power his sister Tara shared with Superman, Kara, no longer too shy to express her feelings for Brion, kisses him and wishes him good luck before she and Rayner regroup with the League. The Green Lanterns manage to shield the village while the others hold down against the hostiles and Supergirl and Green Arrow battle and defeat Silver Banshee and Dark Archer. Deimos gains the upperhand on Warlord until Geo-Force emerges and subdues him. Just as Deimos taunts that he cannot be destroyed as long as the Dark Pillars are active, Swamp Thing emerges and holds Deimos down, allowing Geo-Force to destroy the Pillars, weakening Deimos, who is turned into stone and destroyed in process. Shortly after Warlord thanks the heroes for their help and apologizes to Swamp Thing for his mistrust in him, the Justice League (now joined by Geo-Force, Rayner and Swamp Thing) return back to Metropolis, where Kara and Brion resume their moment together, to the happy eyes of the other Leaguers (including Stargirl, who becomes romantically attracted to Rayner). Sometime later, Kara is introduced to Brion's sister Tara, who is pretty happy to meet her mentor's cousin.
- Jason Marsden as Geo-Force / Brion Markov
- Tara Strong as Supergirl / Kara Zor-El, Robin / Damian Wayne
- Kevin Conroy as Batman / Bruce Wayne
- Peter Cullen as Swamp Thing / Dr. Alec Holland
- Phil LaMarr as John Stewart
- Alan Tudyk as Green Arrow / Olliver "Ollie" Queen
- Vanessa Marshall as Black Canary / Dinah Lance
- Kath Soucie as Batgirl / Barbara Gordon
- Ashley Johnson as Terra / Tara Markov
- Natalie Lander as Stargirl / Courtney Whitmore
- Sam Riegel as Kyle Rayner
- Will Friedle as Guy Gardner
- Corey Burton as Warlord / Trevor Morgan
- Dwight Schultz as Deimos
- J. B. Blanc as Lobo