Yes, I did all this!

Duanmu Mo was originally an ordinary person who traveled to the world of knights and was unfortunately transformed into a monster. However, before the Shocker organization could complete the brainwashing process, a group of Kamen Riders blew up the Shocker base, and he disappeared in the explosion.
Coming to a strange world again, watching the magical girls and monsters fighting, Duanmu Mo realized.
He decided to hide his identity and hide, never show up, and develop carefully... Maybe.
So what he did included but was not limited to:
Turning into a monster and stealing the transformation props of the magic girl, and pretending to meet her by chance after turning back into a human being and showing great concern for her;
Pretending to be a companion of the monster, but after it fell behind in the battle with the magic girl, he stabbed the monster in the back and took away its power;
Standing on the same front as a companion with the magic girls temporarily, and suddenly turning against them after gaining their trust and laughing that his goal had finally been achieved;
After the magic girl was defeated by the monster, he and the monster put pressure on the magic girl until she burst into a new form and then ran away...
——When he was surrounded by the magic girls, Duanmu Mo calmly put the transformation props stolen from the magic girl on his waist and inserted the card containing the monster's power:
"You catch monsters, what does it have to do with me, Kamen Rider?"