We're gettin a pink bean class

It could be like Demonslayer betraying the Black Mage.

Black Mage's pet turns on him.

I also find it funny "The Black Mage" liked the thread...

I think the general consensus is that, lore-wise, Pink Bean has absolutely nothing to do with the Black Mage. The early mentions of him as the Black Mage's minion were either a screw-up on someone's part or has long since been retconned. (I think the same description that called him the Black Mage's minion also claimed that he was summoned from whichever dimension the Black Mage was sealed in, which obviously isn't the case)