Stoica was the Aquos brawler for the Major Twelve Orders. He used Aquos Lythirus.
Stoica made his first appearance in Revelation, he and the other Twelve Orders members were talking about Linehalt and Drago and also about how Drago is too strong. Airzel berates Stoica, saying that he should take things seriously for once.
He reappeared once again in Hostile Takeover.
In The Sacred Orb, he appeared along with Lythirus to battle Marucho and Awkimos. He was doing fine until the Sacred Orb transported all Gundalians the away.
In The Secret Switch, he and Lythirus appeared with Jesse and Plitheon. They battled Fabia and Aranaut and later Dan and Hawktor. Despite his ingenuity, he did not realize that Dan and Shun switched their Bakugan before the battle. He and Jesse ultimately lost, even when Stoica pulled out his Battle Gear.
He appeared in Battle For the Second Shield, saying that Kazarina would have problems.
In Curtain Call, he appeared alongside Kazarina trying to decide who else they can blame for their failures in stopping the brawlers. He decide to blame Jesse but before they can punish him he escapes. Once Ren brings Jesse back he and Kazarina eliminate him. Then on their way to tell Barodius of Jesse's elimination, Nurzak berates them for needless punishment of a fellow operative, Nurzak even claims he can "smell" their treachery.
In Mobile Assault, Stoica goes with Ren to Bakugan Interspace changing into a human disguise. Then he says he wants to hunt humans in their natural habitat and heads to Earth where he brings Koji to Gundalia to be hypnotized by Kazarina.
In Colossus Dharak, Stoica and the rest of the Twelve Orders invade Neathia to destroy the Second Shield. Stoica battles Marucho.
In Dragonoid Colossus, he defeats Marucho while Gill defeats Jake. He retreats with the rest of Twelve Orders when Linehalt uses his forbidden powers.
He reappeared in True Evolution with Kazarina.
In Redemption, he teamed up with Kazarina to battle Nurzak and Fabia. With the help of their Battle Gear, they broke a hole in the floor and defeated them, but later rematched them. This time, Kazarina hypnotized Ren's old team to help them, but Stoica used an Ability Card that flooded the entire arena to attempt to kill Nurzak and Fabia. Somehow, he talked underwater like he could breathe it.
In Final Strike and Dream Escape, he battled Shun to no result.
In Gundalian Showdown, he battled the brawlers on Gundalia with the rest of Twelve Orders. He alongside Gill and Airzel were supposed to go to Neathia to help Emperor Barodius but only he and Airzel left because Gill's ship was supposedly damaged and although Airzel didn't suspect anything Stoica seemed suspicious about why Gill hadn't gone with them.
In Broken Spell, he reveals that he overheard Gill talking with Airzel about Kazarina and forces Airzel to admit that the reason that Gill stayed behind was to kill Kazarina himself. When Airzel was confessing that, Stoica turned on the speakerphone so Barodius can overhear it.
In Code Eve, he helps Emperor Barodius attack Neathia to get the Sacred Orb. He and Lythirius blind Dragonoid Colossus so Dharak could attack him, but Dharak betrays them and all three of them are killed by Dharak's attack.
And he is voiced by Brian Drummond in the English dub and reprised by Mitsuki Saiga in the Japanese dub.