it's a dark plot but a confusing one, unless ryuusei is leaving, there has to be more to this, right now everyone thinks meteor is bad guy, but something isnt right, gentaro and ryuusei had to plan this, otherwise he would have the bad guy to begin with and not go 180 to destroy a human being.
because the episode after that, it's like everything is fine, so gentaro's death has to be a plot of somekind because ryuusei knows alot about switches, he probably knows that cosmic switch will revive him, it's just kengo doesnt know that, but i guess ryuusei trusts him enough that he will figure it out, sort of date joining the greed and going after ooo, of course it was all a trick.