Duruvasa in Mahabharata.
Why was he feared?
What was his motive?
Why does he go on making unreasonable demands?
I don't want to believe in curse.
Durvasa seems to be an eclectic person with a short fuse, and he deems it entertainment [and social justice]- the harassment of people he considers to be [or on the way to be] more powerful than him, like Yudhishthira or Krishna.
Curses are his primary bargaining chip here. However, if we wish avoid 'magic' in the story, we have to interpret these 'curses' as social repercussions, as in, he can use his academic influence to pressure the greater brahmin community (and even the common people) into making his 'curses' come true by excommunicating/dethroning the people he doesn't like.
Also, these brahmins (and many kings and other learned poeple) did have a working understanding of basic scientific principles.
So, for eg. (this is a very rough sketch of an eg.) Durvasa curses a king that his kingdom will have drought for the next however many years. After 'cursing' Durvasa can just bully the irrigation experts into sabotaging the agriculture, and boom, you have drought, and Durvasa is a magician!
Personally, it all seems like elaborate mental manipulations of the right people on behalf of the cursing rishis.


















