the dark booster box Yugioh Beginning 1 Unlimited Sealed 24 Packs Mint – Pokécave Innistrads creatures of the night reign supreme Yu-Gi-Oh! Dark Revelation Volume 1

The low MV and flashback cost of this card give it a ton of power if you have a good board presence

Obviously, it's mechanically suboptimal to do this with legendary creatures, but it's also much funnier

ValuDex is the full picture

Legendary Creature Spirit Noble3/3 Flying Whenever King of the Oathbreakers or another Spirit you control becomes the target of a spell, it phases out

Containing animation and extended Pokdex entries, these cards felt incredibly high tech at the time, but dont always fetch high prices

If there are multiple such effects, they are applied according to the timestamps: the one that was created last wins