|Date of birth||0021|
|Date of death||0075|
|Family||Auris Gaiz (daughter)|
|Affiliation||Capital Defense Corps|
|Japanese name||レジアス・ゲイズ |
|Last app.||StrikerS (ep.24)|
|Voiced by||Bon Ishihara|
He appears to have been named after Toyota Regius.
In his youth, Regius Gaiz was a close friend of Zest Grangaitz, however, their careers later took different paths: Zest became a field mage, while Regius displayed little magical talent and instead aimed to become a general, having been frustrated by incidents involving criminal mages that resulted in innocent people being killed.
It has been revealed late in StrikerS that in his ambition to increase the significance of the Ground Forces under his command, he made deals with Jail Scaglietti. When Zest and his team were about to discover one of Jail's hideouts, Regius attempted to have Zest put onto another assignment, only for Zest and his team to depart prematurely. Zest and Quint Nakajima were killed on the mission, and Megane Alpine went into a coma.
In StrikerS, he opposed the creation of the Riot Force 6 from the onset, because of both TSAB Navy's (whom he saw as a rival) support of it, and its commander Hayate Yagami's "criminal" past, referring to her role as a former master of the Book of Darkness. He attempted to have Section 6 investigated in order to work against it and the Saint Church, but was unable to make any significant progress toward that goal.
Regius was shocked to learn about Jail's attack on the Bureau and of Zest's return as an Artificial Mage with the memories of the original. Zest eventually confronted Regius with it in the final episodes of StrikerS, asking where the justice the two had fought for was and why his team had been sent to their deaths. Before Regius could answer, Jail's Numbers, Due revealed herself and assassinated him, only to be killed by Zest. Zest himself was killed by Signum soon thereafter.
His burial was seen to by his daughter Auris.