Slifer the Sky Dragon The heavens twist and thunder roars, signaling the coming of this ancient creature, and the dawn of true power. That is the card description on the original Slifer card
"Red-Eyes Dark Dragoon" is particularly powerful, and is worth using even if it forces the inclusion of "Dark Magician" in the Deck, while "Meteor Black Comet Dragon" and "Red-Eyes Slash Dragon" are more flexible alternatives, requiring any Level 6 Dragon monster and any Warrior monster, respectively, as their second material
Because of this new synergy, I've relabeled archetypes featuring three or more copies of Unholy Annex as Golgari Demons, distinguishing them from Golgari Midrange versions without the card
Although each type of draw engine can function in a different way, each with its own unique gimmick, the overall purpose of these cards is to allow you to add cards from your deck to your hand