In terms of what Commander Bracket this deck belongs to, I would also place it firmly in Bracket Two
Your thing can be basically anything, but this is easiest to see if we look to Kindred decks having a critical mass of creatures of your chosen type and/or cards that care about that type is crucial to amassing synergies and building a board
Saruman of Many Colors Saruman of Many Colors has a fairly daunting text box that boils down to stealing enchantments, instants, and sorceries after casting two spells in a single turn
So while it is effective for identifying an Alpha Rare, it is not definitive in identifying a Beta rare from re-backed ICE or CE
The five basic land typesPlains, Island, Swamp, Mountain, and Forestproduce white, blue, black, red, and green mana respectively
Playing the exiled cards will make you Treasure tokens, and if there are any left over by the end of the turn, you will still get mana by creating those Spawns