mindbender
nounUK /ˈmaɪndˌbendə/
US /ˈmaɪndˌbendər/
Something that is very hard to understand or figure out.
That puzzle was a real mindbender, and it took me an hour to solve.
OTHER MEANINGS
2. A person who changes or influences how others think.
The charismatic speaker was a mindbender who made everyone question their beliefs.
3. A story or movie with a surprising plot that makes you think hard.
The film was a mindbender with a twist ending nobody saw coming.
4. Something that is confusing or mentally exhausting.
The complicated rules of the game were a total mindbender for new players.