Some include a physical or vocal component, like Blacker Lotus or the Gotcha! mechanic on Touch and Go, some have rules that specifically reference flavor text or artists, like Carnivorous Death-Parrot and Drawn Together, and some require interacting with people or objects outside the game (Ashnod's Coupon being my favorite)
Sower of Discord is a fun one, especially if you have more than two opponents to pick from giving you a chance for some fun politicking
BOOSTER ACROSS TIME [BT-12] BT12-001 U Digi-Egg Lv.2 Gigimon Color Red Form In-Training Attribute - Type Lesser DP - Cost - Digivolve Cost 1 - Digivolve Cost 2 - Upper Text - Lower Text [Your Turn] Add 1000 to the maximum DP you can choose with DP-based deletion effects
WR: PILOT AGGRO In my experience RW has been by far the best pure aggro deck in the format, relying on a few specialized uncommons and the wealth of strong 2- and 3-drops in these colors
It can also disable The One Ring, though you'll likely avoid this interaction since you run it, too
