Dr Jung; the Lady of Ten Suns.

Dr Jung is a sorcerer-scientist; she has magical power over the sun and light, as well as being an incredibly intelligent scientist.
Unfortunately, she lacks the sense to recognise the harm her powers and experiments cause. She once plunged an entire country into eternal daylight, causing mass disruption to people's lives and the ecosystem. She had no idea that she had caused such chaos until two adventurers near killed her and made her undo her spells.
To this day, she still doesn't understand why that was a problem; everybody likes a sunny day, right?