Board: All That's Left

Love the expression on his face

Theory about Chase could be (or maybe someone else) as the new Kamen Rider Mach:
Theory 1 = his transformed form known as Mashin Chaser. Look at the two first alphabets. MAshin CHaser. Get it? First clue here.
Theory 2 = he rode a bike. If I remember, in the catalogue scans said that the bike can also combine with the Chase's bike.
Theory 3 = "battle against his rival, KR Drive". If Knight can fight against his rival Ryuki, Gatack against Kabuto (prominently in the series' penultimate episode), Ixa against Kiva, Meteor against Fourze and Baron against Gaim in the early episodes, then all I can think is Mashin Chaser could be a corrupted version of Mach before his evil form gradually collapsed one by one, revealing his true form of himself.
Theory 4 = Chase might be brainwashed or mind-controlled by Roimude's highest commander (higher than Heart and Brain) and then modified to become a Grim Reaper. Must be someone who responsibility to modify Chase into a senseless monster.
Hot 18+ Fellatio plz don't ban
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good joke