Speaking of Alastair Reynolds, concept of Pattern Jugglers - benign algae-like pools that oscillate in strange image-like patterns and can physically connect, read, and modify human brains. A person entering the Pattern Juggler could experience someone else's life, temporarily gain skills or knowledge, or... die.

In Ursula LeGuin's Left Hand Of Darkness, I love the idea of society without war. There is still violence and murder, but fighting on someone else's behalf must be viewed as incredibly absurd and unacceptable.

Department Of Truth comics are based around the idea "what if what we believe becomes true?". So cryptids, UFOs, and conspiracies exist because enough people believe in them.

The depth and mechanics of Orogenes in N.K. Jemisin's Fifth Season / Broken Earth. It's not just "I cast frost", it's heat and energy manipulation, with sense, direction, and geometry.