Please read these previous posts just because.
Magolor isn't in the main cast. He's basically in a similar position to the Cappies in the show, as one of the residents of the town. He's the mysterious shopkeeper dude who talks funny and sells things at ridiculous prices (though is willing to give some stuff away if you're REALLY on his good side... sometimes...)
He also probably has a gun somewhere just because. He has a lot of weird stuff. Probably has a book of ancient legends that Adeleine reads one day and then finds out about the whole prophecy surrounding Kirby from it
If I were to allow him be important to the plot, he'd probably just help Kirby cheese through, like, everything because he still has his OP powers from the games (though you never really get to see him use them. Maybe once or twice it'd happen?)
He's a good egg tho. Very good egg
(Don't worry, I'll make another main character post later. Currently working on it. Just felt like doing this to celebrate the formation of the Magolor Protection Force)