烧脑

烧脑	shāo nǎo	(neologism c. 2016) (coll.) (of a situation, problem or piece of content) intensely demanding on the brain; brain-bending
烧	shāo	to burn / to cook / to stew / to bake / to roast / to heat / to boil (tea, water etc) / fever / to run a temperature / (coll.) to let things go to one's head
脑	nǎo	brain / mind / head / essence