Consider Ravenous Chupacabra and Royal Assassin
There are a number of resources out there that allow you to plug in your decklist and get a breakdown of what percentage of your cards need specific colors of mana, what the average converted mana cost of your cards is, and other helpful information (Im partial to Tapped Out personally)
Im pretty firmly anti-milling opponents when it comes to conventional Cubes, and rad counters also have similar problems to the initiative and The Ring regarding having rules text that isnt printed on the card
Regal Force At the very least, [c]Regal Force[/c] will draw you a single card when it enters the battlefield, as it counts itself as a green creature
Chimeric Idol was the best three drop in the game for two years on pure efficiency terms, and it is an artifact
This inspiration comes in what I explained in my previous article I has dubbed, Izzet June, as both articles for the month have focused on Blue/Red decks of different flavors