So I vaguely remember that he extorts Donald economically to force him onto adventures he doesn't want to go on (he's his landlord I think).
I couldn't remember for sure so I tried googling it, and this thread came up and it's so much worse than I thought. Scrooge McDuck gets the
CW (racism and colonialism)
Here's the top comment from that thread, it's the reason for the CW so I'm gonna spoiler it:
spoiler
In Life and Times of Scrooge McDuck, it is shown that Scrooge used the credulity of african tribes to unfairly get their mines. When one of the tribes leader refused and humiliated Scrooge, he became so angry that he hired men to destroy the village and then tricked the tribe leader to sell the mines to him. This event is what triggered Bombie the zombie in season 2 as the tribe leader seeked revenge against Scrooge. But it is also the reason why Mathilda and Hortense (his sisters) decided to take some distance with him as they couldn't recognize their brother anymore.