Just Caelid things

Ditto for SMT Nocturne. Random enemy accounters can occasionally take initiative. Some spawns have extremely brutal movesets between crits, ailments and instakills (which are horrifyingly effective against player units in this game). Since it's game over if the main character dies, you could get booted back to your last save by an unlucky encounter with a half dozen demons dogpiling you before you have the chance to do anything. This can happen as early as the first city.

Later, this charming calcium man voiced by Keith Silverstein accosts you in a sewer to steal your candles, and he 100-0's your whole team in Phase 2 unless you learned Sukunda and fused Bicorn. The whole game's basically like this, it's hilarious.