Yu-Gi-Oh! 10 Powerful Cards So Good They Were Banned!

Bardiche was a rank 3 Warrior monster who required any 2 or more dark monsters making it very easy to summon in almost any deck. It's effect allowed its user to send 1 'Phantom Knights' monster from their deck to the grave, and then set 1 “Phantom Knights” spell or trap directly from their deck, and if a dark Xyz Monster was special summoned to a zone it pointed to, you could destroy any card on the field.

The most common play was sending 'Silent Boots' to the grave for 'Fog Blade', then banishing 'Silent Boots' for another. Allowing the player to search 3 cards per turn while managing to thin their deck. With its link markers in the corners you're almost guaranteed to blow up a card, potentially on your opponents turn by using the 'Fog Blades' you searched to summon a 'Phantom Knights' Xyz monster in your grave, triggering it's destruction effect and stopping your opponent's plays.

Coupled with how easy it was to bring out in any deck using only a few Phantom Knight support cards, and how it's cost was actually a combo in of itself, its no surprise that Bardiche ended up getting abused and earning it's spot on the list.