Dex Stewart

Prince Dex is an ally of the Thunderstorm Power Rangers, and the main protagionist.

History
He is a prince of the planet Edenoi, homeworld of Gamma 5, and the current Masked Rider: the guardians of Edenoi. As with all his race, he possesses a gem in his forehead that channels various powers, including broadcasting his memories into thin air.

Dex's grandfather, King Lexian, gave Dex the Masked Rider powers when the planet was attacked by Count Dregon - Dex's uncle, and a tyrant who coveted the powers for himself. While the planet fell, Dex continued to lead the resistance to his uncle's tyranny.

He encountered the Thunderstorm Power Rangers during a battle, where he initially thought they were working for Dregon. After a brief fight, the heroes teamed up to take down the tyrant's Plague Patrol and Cogwarts. The Rangers and Dex departed as friends, but it was now clear that Dregon was turning his sights towards Earth and Dex would need to travel there to stop him. A Friend in Need

The Rangers mentioned their adventure helping him when they were considering asking the Alien Rangers for help. Alien Rangers of Aquitar

Dex would disguise himself on Earth as a human called Dex Stewart, meeting new friends on the new planet as he battles Dregon. Masked Rider

Relationship with Kelly Harper
As a student at Leawood High, Dex meets Jenna's best friend, Kelly Harper, a beautiful reporter and a cheerleader who lived next door to the Stewarts. While Jenna and Kelly's nemesis, Pasty flirted with him, Dex developed romantic feelings for Kelly. She often did homework with him and Jenna. When Count Dregon kidnapped Kelly, he rescued her, but the incident cause Kelly to find out that Dex was Masked Rider.