Little is known about Rogles' past. He is one of the two sons of the former king of the darkworld, Kaiza, along with Megas. Although Megas was supposed to inherit his father's throne, Rogles and Kaiza himself conspired together against Megas to kill him, but they weren't successful and before their failure would be known in public, Kaiza banished Megas into a void dimension. Rogles became the dark world's king some time after.
During the events of the first game, Rogles locked away Vanity's source of positive energy within a precious stone known as the Fantasm Jewel and broke it into fragments. By manipulating negative energy, he weakened Vanity and upset the balance of justice in Reality. Before attempting to face Rogles, it was necessary for Yuuko to reunite the shards of the Fantasm Jewel to release the full power of Valis.
Anticipating interference from the Valis warrior, Rogles created his own warrior by granting special abilities to Reiko Kirishima, a troubled girl from the human world as well as an acquaintance of Yuuko. The final fragment of the Fantasm Jewel was entrusted to her as well. Reiko was ultimately killed by Yuuko in battle; as a result, Yuuko vowed revenge on Rogles, who awaited her in his castle in Vecanti. Rogles was lastly defeated and killed by Yuuko in his castle.
In Valis III Rogles reappears; here he is resurrected by Glames who consults him about Yuuko and the Valis sword. Glames then makes Rogles one of his generals granting him another chance of fighting Yuuko. Rogles knew about Glames's true intentions of proving his power instead of saving his own people; he warned Glames that his pride would make him fall, but Glames didn't take him seriously. Rogles was sent to the dark world's cemetery to fight Yuuko once again in his two forms, but he lost and died again once and for all.
Rogles is an evil, cruel and merciless king. Being powerthirsty since he was young, Rogles does everything he can in order to grow more and more powerful, from betraying his own family members (like he did with Megas) to using innocent people's dark emotions to his own favor (like he did with Reiko), although he seems to be quite good with his servants (like his main generals). He is also capable of easily finding out about anybody's true intentions by just looking at them.
He looks down on weak opponents and is interested in strong ones. He also likes to play with his betrayers by sending them into fatal traps. Rogles doesn't like to fight the weak himself. He instead makes his generals to do the work for him.
In Valis III, when revived by Glames, he seems to be calmer, more calculative and taciturne than before.
Rogles is a skilled offensive mage. He can levitate, throw energy balls and lasers against his opponents and uses a flaming dragon that, in turn, fires at his targets.
When in his second form, Rogles can move faster and adds to his aforementioned powers. He can now use a wide slash and explosion spells; he also has a giant morning star as a melee weapon.
In Valis III, as Neo Rogles, he has almost the same abilities but he can now use flame arrows (like Yuuko herself) and spinning knives.
Rogles appears in Valis I as the main antagonist in all of Its versions and the final boss in all except for the NES one. He tries to take over both Vanity and Reality but is stopped and defeated by Yuuko.
Rogles appears also in both home computers and console versions of Valis II. In the home computers versions (SX68,PC-88/98) a statue of him is used by Gaias to fight Yuuko before confronting herself personally. In the PCECD/TGCD version, Rogles appears in Megas's flashback when he tells Yuuko about his past.
Rogles appears in Valis III, first in the introduction scene and then as one of Glames's main generals. He is one of the last bosses in the game. He is once again killed by Yuuko.
Rogles is also one of the villains in Valis X.
Rogles appears in both the old and the new manga adaptions of Valis. In the first one his appearance is based on the one he has in the NES version of the game.
In the new manga, his appearance remains as the original one and his role and character is almost the same as in the games.
- Rogles is the only main antagonist from the series to never reveal his true face: he always uses his mask.
- Rogles is the only main antagonist from the series that never killed anybody on screen.
- Rogles is the only main antagonist from the series who used someone from the human world (Reiko Kirishima) to accomplish his goals.
- To the date, Rogles is the only antagonist to have reappeared cannonically again when he was revived in Valis III.
- There is scrapped code from Valis III hinting that Rogles was initially supposed to have the possibility of fighting any of the three playable characters from the game, but in the final version he can only be fought with Yuuko.
- In the game data of Valis IV's PCECD version there are many unused sprites. Between them there are many Rogles sprites in his Valis III's form meaning that he was supposed to reappear once again in said game but was discarded from the project.
- The Famicom version of Valis I is the only version of the game to not have Rogles as the final boss.
- One of Rogles's concept arts have a slight resemblance to Gyeda, one of Rogles's generals.
- Hammer Guarder, a boss from Valis III, has some resemblance to Rogles's first form and also uses a morning star as a weapon.
- Rogles has the largest army of any antagonist in the series, with a total of 9 generals (following the PCECD/TGCD's chronology), and also one of the most varied between versions.
- Rogles's relation with his army is similar to that of Megatron and his Decepticons from the Transformers franchise: while his most ingenuous henchmen are the most loyal to him, his intellectual subordinates are truly power-thirsty plotters that try to eliminate their leader and assume his position.