While it isnt as common as some, the utility makes a difference
By Invitation Only (Innistrad: Crimson Vow) How often does your opponent have more than 13 nonland permanents when you untap and start your turn
Check out one of the darkest sets MTG has ever put out, with excellent spooky reimaginings of classic, corrupted characters
Thats because it has been revealed that the rarest, most sought-after card in the entire new Lord of the Rings expansion of Magic: The Gathering has been found
Outpost Siege is certainly the best at generating resources, but this deck does not have anything in the late game as powerful as Soulfire Grand Master loops, and I doubt Outpost Siege reverses the arrow of inevitability in our favor, so I favor something aggressive
(It loses all colors and all other creature types.)