yugioh card seal of orichalcos Yugi Muto and The Sleeves 50 Pack – Realgoodeal A single individual card from the Yu Yu-Gi-Oh! fans may recognize this

Of course, another trait that makes it valuable is that this particular printing has the Professor Program seal on the bottom right

If not, the investment won't really do anything to stop your opponent

When an opponent's monster declares an attack: You can Special Summon this card from your hand

Then on top of that - as if just an afterthought - it comes with Avacyn, Angel of Hope's ability (minus indestructibility for itself) and makes it accessible for any color

Let's say you cast a Glorious End during your opponent's last turn, if you can untap, play a Gideon of the Trials and make an emblem, you won't lose the game to Glorious End, which means you just Time Walked your opponent for three mana in Standard