As the online game for the era, King of Pantheon had long since reached a stage where one did not need to use their limbs to play the game. It could be played with nothing more than one's brain.
There were specially-abled players in reality who were no different from other players in the game. The ones without arms had arms, the ones without legs had legs, and their limbs felt just like they would in real life.
(Let me just digress a little here and call BS on those online game novels where the main character gains all sorts of superpowers and attributes as soon as they enter the game for some crazy reason or another. I seriously hate those. I mean, OP powers are fine, but as an online game, no matter how you look at it, everyone should at least start on equal footing, right?)