Toriiver

The Toriiver (鳥居バー) is the transformation belt of Era Saga as Kamen Rider Nio. Originally intended as a set of "training wheels" due to his lack of control, it takes the Flames of Ari absorbed into an Omamari and converts it into Nio's suit. After Era begins studying Moriteryu in earnest and through his battle with Kamen Rider Maō it evolves into the Toriiver Off (鳥居バーオフ), which can now boost the flames' potency and retrieve it from the "smothering" power of some Enmi, as well as absorb their essence in general. It changes form and color when Era transforms, matching the overall color scheme of the Nio armor.