Tronos Madu is a supporting character in Part 2 of 3Below.
He was one of the bounty hunters who was sent by General Morando to eliminate House Tarron by killing Aja and Krel and bringing the life cores of King Fialkov and Queen Coranda to Morando so he could destroy them. However, Tronos wasn't looking for a bounty, but vengeance against House Tarron for letting his homeworld of Voltar be torn by war. He eventually redeems himself after realizing that Aja could understand his feelings.
Tronos was a Voltarian who lived peacefully in the planet of Voltar. However, war struck in said planet, so his people begged the King and Queen to put an end to the war. However, they refused to listen to their cries, so they left Voltar to be ripped apart by the war. Devastated, Tronos has been plotting his revenge on the King and Queen ever since.
At some point, Tronos became one of Morando's bounty hunters to hunt down the Royals by killing Aja and Krel as well as taking the life cores of their parents so that Morando could destroy them. However, Tronos saw this not as an opportunity for getting his bounty from Morando, but for getting his vengeance on House Tarron.
After Varvatos is rescued by Aja and Krel, Tronos tracks the Mothership all the way back to Earth, so he uses electrokinesis to travel through Arcadia-Oaks's electric grid to find the Royals, causing a major blackout in the process. He is able to find them in the museum, but Toby, AAARRRGGHH!!!, and Aja force him to retreat. However, Tronos soon finds Aja and Krel at their garage. Using an upgraded version of their "lightning-in-a-bottle", they try to capture him, but he escapes once again and takes them with him until Colonel Kubritz and her minions capture him.
While Tronos is being contained in the secret military base of Area 49-B, Tronos and Kubritz make a deal to take Aja and Krel captive, that if he gets their cores, then she will give him Akiridion technology in return. Later on, Kubritz turns Arcadia Oaks-High into a quarantine zone with the help of her men. At the corridors, Tronos ambushes Aja and Krel, and he and Kubritz capture them. Following this, he reveals to Aja that he was not looking for the bounty, but revenge on the King and Queen for leaving his planet's population to die. However, Toby Domzalski and Eli Pepperjack help Aja and Krel escape, so Tronos tries to kill the latter two before Kubritz stops him and has him recaptured, even though this wasn't her and Tronos's deal.
Eventually, Morando lobs an asteroid the size of Arcadia-Oaks at Earth to destroy Arcadia along with the entire Western Seaboard. When the Royals (along with Toby, Eli and Kubritz work together to try to stop the asteroid, Aja goes to Tronos's cell, telling him to power up Krel's laser and save Arcadia by destroying the asteroid. At first, Tronos refuses because if House Tarron gets killed by the asteroid, he'd happily go down with them. Aja then enters the cell and reminds him of the destruction of Voltar, but this causes him to attack her, only for her to tell them that they can both be better than her parents. With that, Tronos redeems himself after realizing this, and powers up the laser with his electricity to destroy the asteroid. However, Kubritz betrays House Tarron and reveals that the deal was a trap that she set up to capture them, while Tronos berates her for betraying him and House Tarron. When she and her men incapacitate Tronos, the Royals leave him behind to be re-captured.
When Kubritz shows Morando a tour of Area 49-B, she takes him to Tronos's cell, where Morando demands for him to be released because Tronos is his bounty hunter. Kubritz releases Tronos from his cell, only for Morando to stab him with his red serrator to vaporize him to his death.