Overview
The concept is simple: break the board and swing with a massive Gren Maju Da Eiza. Naturally, this means you must include cards that mass banish. Luckily, there are a multitude of cards that fulfill this condition. Otherwise, the rest of the deck is split between breaking the board and draw power.
Mass Banishing
Of course Pot of Desires is a staple for this deck, providing consistency and 4000 ATK right off the bat for Gren Maju. Also, this deck may be one of the only ones that would enjoy activating two Desires in a game! However, some lesser-known cards provide mass banishing as well. Gizmek Orochi, the Serpentron Sky Slasher is a fascinating card that mirrors the likes of Fairy Tail Snow. Perhaps the most synergistic card in the deck, Gizmek Orochi provides a beatstick, mass banishment, material for Rank 8 XYZ monsters and removal on command. Even decks that can handle Pot of Desires' negative effect could not handle constantly banishing eight cards face-down from the top of the Deck. However, for Gren Maju this only provides fuel.
Golden Castle
Golden Castle of Stromberg also makes its competitive debut in McNabb's Deck. It served as the main defense, a board breaker, and a combo extender. A key aspect to these mass banishment cards is that they all carry so much weight and diversity - there are rarely any cards you don't want to draw. Stromberg will always be on the board, considering the consistency between Trade-In, Pot of Desires, and searching cards such as Terraforming and Glife the Phantom Bird. As long as Stromberg is on board, the opponent can't attack, unless their monster can get through its destructive blowback (and I can guarantee you, someone has attacked into it without reading). Again, Gren Maju decks are the only decks capable of bearing the constant banishment due to its upkeep cost. It's a funny thought that if you have no more S/T removal, this card alone might end the game.
As a side note, McNabb played Barricadeborg Blocker, a generic link-2 monster. It can add back Stromberg if you need it or could block it from being destroyed. Decks that lack S/T removal are put under an attack soft-lock by this.
Eater of Millions is the most common card among the mass banishes. It can get decently large on its own, but its main purpose is to banish problem cards. It can also function as Link material, since it's a free special summon.
Removal
There is a TON of removal in this deck. Notice that there are no hand traps - that is because McNabb's deck is that good at breaking boards. Dinowrestler Pankratops and Super Polymerization are common removal cards, but as mentioned the mass banishment cards also serve as removal. The Galaxy-Eyes XYZ line-up also does a decent job at clearing the board or baiting out reactive traps or quick-play spells. Golden Castle of Stromberg can Special Summon Hexe Trude from the Deck if Gren Maju doesn’t need to be summoned that turn.
Draw Power
Traditional cards include of Pot of Desires and Trade-In. Danger! cards draw and help Rank 8 or link plays. The draw power in Gren Maju is so important that McNabb elected to play Called by the Grave to protect it from children with large foreheads. While McNabb's deck provides some grind game and removal, it must still draw Gren Maju Da Eiza to win consistently!
Why Was a Gren Maju Deck So Successful?
Ironically, the shift in tone of the meta to more grind games happened to be in favor of Gren Maju. In this grindier meta, having hand traps combined with one trap or quick-play disruption is enough to survive until the next turn. McNabb’s Gren Maju deck is unique in that it forces the opponent to either lose the grind game by breaking their board or prevent that and lose to an 8000+ ATK swing.
Will Gren Maju Continue to Be Successful?
While it appeared coming out of this YCS that the answer was no, the Gren Maju deck was able to adapt. A different, more Danger! heavy variant of the deck ended in 1st Place at YCS Niagara Falls recently. While it left behind the Golden Castle banish synergies, it still kept the core of banish heavy cards that made McNabb's deck so successful. While it's definitely not a tier 1 meta-destroying deck, it's safe to say that Gren Maju OTK will continue to pop up in top cuts going forward.
