City of Brass isnt Standard legal
(In fact, token cards have various effective rarities, but for card code purposes they are listed as a single rarity.) Yes, currently in Magic card codes there are seven options for the rarity field: C Common U Uncommon R Rare M Mythic Rare L Land (This refers only to basic lands
Red/green: Power Matters Aggro It does seem like Wizards deliberately tried to keep most color pairs within their very safe, traditional mechanical territory with Tales of Middle-earth perhaps acknowledging this set might draw in less experienced Magic players
Firstly, as a counter to enemy board-wipes, where it can essentially close a game by wasting a control players best answer along with their turn
As a ramp engine, sadly Relics of the Rubblebelt isnt all that, since only one Conjured Signet goes onto the Battlefield