These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Game Breaker: Summon Circles. Activate, get into relatively straightforward fight, recieve a redonkulus amount of XP and goodies, repeat. Level Grinding has NEVER been this easy!
God Damned Bats - Literally, there are damned bats in the haunted mansion area, which if you don't react quick enough, will drain your life to zero in 10 seconds or less. You can't even kill them, which makes it worse.
That One Attack: Terracor's curl, the possession attack of the two Shade bosses (which, in addition, can potentially kill any possessed party member so the bosses can recover part of its energy) and Mystic Spider's swallowing attack.