It evokes Celtic and Scandinavian vibes, which is right up my street
Elesh Norn, Grand Cenobite is high on the list because, well, its one of the premier reanimation targets
The main thing that holds it back from being higher on the list is that it doesnt necessarily end the game itself
4 Mage Slayer + Jumbo Cactuar Make Sure It Hits Less of a silly combo and more of an assurance, Mage Slayer is a powerful but often overlooked piece of equipment by many Magic players
Bad Mechanic Hosers (Nine-Ringed Bo, Tombfire, Root Cage, Trapfinder's Trick, etc) There are a number of mechanics Wizards of the Coast were clearly worried about when they printed them
No two symbols from different sets are the same to prevent confusion