That being said, I think the reasons for a card being banned can be broken down into two main categories: A card is too powerful on its own and almost every deck has to have it to be good
Legendary Creature - Human Spider Hero Removal (CTRL to add secondary) Tutor The Seriema When The Seriema enters, search your library for a legendary creature card, reveal it, put it into your hand, then shuffle
and perhaps in combination with spells like Brainstone or Mystic Speculation
Rarity: M Cost: 1WUB Pow/Tgh: 5/4 Card Type: Legendary Artifact Creature - Robot // Legendary Artifact Artist: VOLTA Creation // VOLTA Creation Name: Soundwave, Sonic Spy // Soundwave, Superior Captain Finish: Regular Card Number: 014/015 Set Name: Transformers
So, yeah, combine that with the Exeggutor or the Celebi and crikey, youre in business
#2: Obelisk the Tormentor During his Battle City tournament, Kaiba sought the ultimate power of all three Egyptian God Cards after being gifted the mighty Obelisk the Tormentor