Head writer Noboru Sugimura writes this one. I love this episode. I knew that something was going to happen at the end, but what actually happened blindsided me. And the motive for it -- this is why I consistently say that Ryuichi Takaoka is one of the most twisted villains in tokusatsu. And I have news for you: the worst from him is yet to come.
The cinematography and writing of the ending on the roof is masterful, probably the best in the series. It reminds me so much of the end of Empire Strikes Back, a feeling of darkness yet to come as Daiki wrestles with his emotions.
After you finish watching the entire Solbrain series, go back to this episode and take a look at the entire scene where Takaoka calls Imai. The ending isn't something they just pulled out of thin air, it's shown in this episode clearly.
In other news, if you're used to skipping the opening, it has changed as of this episode to include Ryoma/Knight Fire and the Pile Tornado.
Torrent Link: https://www.nyaa.se/?page=view&tid=887407