Personality & Character
Regene is an ambitious, self-righteous, arrogant, and hubris double-agent. While the full spectrum of his motivations and reasons aren't explained, Regene has his own visions of enacting Aeolia's plan, repeating a similar ambition to Ribbons Almark. For the sake of achieving his own goals, he has no problems betraying fellow Innovators. He easily switch his allegiances to Celestial Being, helping Wang Liu Mei achieve her own goals for the sake of an incomplete-described motive.
Skills & Abilities
Regene is like all Innovades, able to utilize quantum brainwaves to telepathically communicate with other Innovades, utilize quantum networked devices, and endure in the harshness of space. Unknown to Regene, Ribbons modified him and the rest of his fellow Innovators to have a backdoor to their eyes and minds. Ribbons made his group that way to make sure there was no betrayal and/or deception amongst his own ranks. In chapter 12 of Mobile Suit Gundam 00I, its confirmed that Regene has the ability to control all machines that are installed with GN Drives, including originals. First time we see him use it is at the end of chapter; Regene was using this power to control the GNZ-001 GRM Gundam.
Regene Regetta briefly appeared at the end credits of the season one finale alongside Louise Halevy, wearing the Earth Sphere Federation uniform. His heavy resemblance of Tieria Erde initially led fans to confuse him with the latter after the episode was aired.
In the second season, Regene is shown to be working with the Innovators, often being seen close by Ribbons Almark's side. Curiously, he was absent from the Innovator lineup at the end of the first season.
Regene has high connections within both the A-Laws (often contacting Homer Katagiri at the behest of Ribbons) and the Earth Sphere Federation. When the Twin Drive system of the 00 Gundam is first activated, Regene snidely comments that Ribbons does not know about it despite having access of all seven levels of Veda.
Despite apparently working underneath Ribbons, Regene often acts of his own will. In episode 7, Regene locates Tieria, who is searching for the MIA Allelujah Haptism on a remote island, and appears before him in an almost angelic apparition. Tieria is surprised to see someone with the same face as his own, and Regene explains that they share the same DNA (with an identical base sequence pattern of "type 0988"). Using a similar sort of telepathy to the one that previously enabled him to communicate non-verbally with Ribbons, Regene tells the mildly hallucinating Tieria of Aeolia Schenberg's plan, and leaves him with an offer to join the Innovators. When Tieria later asks Ribbons if the meeting occurred on his orders, Ribbons responds that Regene's "little prank" was not of his doing, and during the unveiling Ribbons had commented that what Regene was saying was highly unnecessary.
Regene later pays a visit to Wang Liu Mei and leaks information of the A-Laws party to be passed on to the Meisters, thus setting up the meeting of Ribbons and Tieria. While he does not attend the party himself, Regene watches the two of them dance from outside dressed in a suit. He later muses to himself that Aeolia Schenberg's plan had been modified due to his attachment to those involved in the first step, possibly as a result of either Ribbons' or Celestial Being's doing.
It is later shown that the "recruitment" of Tieria Erde was entirely Regene's idea, believing that it would accelerate the progression of Aeolia's plan. Ribbons and Hiling Care tell Regene that, on the contrary, they need Celestial Being as their enemies in order for the "plan" to be carried out. Both Ribbons' comments and Regene's doubts seem to imply that the plan Ribbons is following is not the original one devised by Aeolia Schenberg, but rather a corruption of it altered to suit Ribbons' own ideals. This is later confirmed when Tieria Erde, after regaining full access to Veda, divulges the true nature of Aeolia's plan, and thus reveals how much Ribbons has warped it from the original.
Regene makes a cameo appearance during Chapter 9 of 00I. He appears briefly to convince Telicyra Herfi and company that he is the missing sixth member of their group. However, Telicyra sees through this as a lie, stating that Leif was about to kill him but didn't for the sake of his mission. Telicyra then identifies an Innovade Gundam Meister with a similar appearance to that of Regene (presumably Tieria Erde) within Veda's data banks. In chapter 12 of 00I, it's confirmed that Regene has the ability to control all machines that are installed with GN Drives, including originals. Regene was using this power to control the GNZ-001 GRM Gundam. He uses his power to control GRM Gundam to attack the group, but Fon quickly ran over to stop him. Fon grappled Regene and choked him till Regene's awakening completed the gathering of the six comrades. Veda tells each one of them the true purpose of the gathering of the six comrades. Their role is to become the new observers and to perfect Aeolia Schenberg's three part plan, GN Drive, Veda, and Innovators. Ribbon at the same time took control of Regene's body to find out the truth of the six comrades. Furious, Regene doesn't want go along with Aeolia's three part plan. He quickly escaped, abandoning the GRM Gundam. On his escape route he contacts Beside in the 1.5 Gundam to the attack the orbital elevator. To prevent Regene from harming them again Hermiya's uses her ability to manifests itself or to reset the memories of other Innovades. She invokes her power to erase all memory of Regene's involvement with the six comrades.
Going Against Ribbons
Starting to work against Ribbons, Regene deliberately gave Wang Liu Mei the coordinates of Veda and ask her to follow his instruction by giving it to Celestial Being. He is later slapped by Ribbons, and being verbally punished for the attempted treachery. He is later seen at the site of Setsuna's and Graham Aker's battle, watching the true power of the 00 Raiser's Twin Drive System in action and remarking on it with a sense of satisfaction. At this point, it is revealed that Regene has indeed been pulling strings behind Ribbons' back and is working towards a plan of his own which is shown to be much closer to Aeolia's ideals than previously indicated, however he still states that it is his own plan, neither Ribbons' nor Aeolia's.
After supposedly disposing of Ribbons, Regene resolves to take full command of the Innovators. This triumph is short lived however, as Ribbons revealed himself to be alive and that Regene killed only a clone that Ribbons created in the event that Regene betrays him. Regene attempts to shoot Ribbons, but is fatally shot by Ali al-Saachez. His body was left lying on the floor as Ribbons unveiled Celestial Being.
However, in the ensuring battle, when Setsuna/00 Raiser initiated TRANS-AM Burst, Regene's voice is heard by Revive Revival, who assumed that the phenomenon was created by the Gundam; Regene corrected him. He explains that Setsuna is the only true Innovator, who, when linked to the Twin Drive, purifies the GN particles and enhances people consciousnesses; he make a remark to Setsuna that his Innovation is now complete. He later speaks to Ribbons Almark as he removes Ribbons' link with Veda, saying that he will not allow his plan to succeed; he had merged with Veda. He seems to awaken Tieria and transfer his consciousness into Veda as well, who then activates the Seraphim Gundam along with its TRIAL System. It would seem now that Regene Regetta is the only Innovator that has been remotely loyal to Aeolia's original plan, as he has intentionally led Celestial Being to this point of fulfilling it.
Due to the events in season 2, Regene is no longer an Innovade, but a part of Veda as a living consciousness.