Green has a huge stable of artifact and enchantment removal, so having a spell with additional functionality is quite good
You can then summon the Xyz monster from your Extra Deck, with a Rank equal to those monsters Level (example: A Rank 4 monster for two or more Level 4 monsters), placing the monsters used for its summon underneath the Xyz monster as Xyz Materials
Marneus will trigger when one or more tokens enters the battlefield
Gandalf of the Secret Fire is an awesome spell-slinger commander, Witch-King Sky Scourge provides another option for Wraith tribal, Aragorn Hornburg Hero can quickly make aggressive creatures gigantic, and Galadriel works great for go-wide or token strategies
Cards in the expansion offer diverse abilities like continuous trap searches and hand traps
"Counter Gate" resolves and Kaiba draws (from the ground rather than the Deck) "Obelisk the Tormentor"