Omarthis, Ghostfire Initiate puts all that mana to good use by taking its double X casting cost, and turns the mana into +1/+1 counters
It was purchased by famous YouTuber Logan Paul for the astonishing amount of $5,275,000.
I think this is one of Greens best Commons This 3/1 trampler is going to be able to come back from the graveyard a ton in this format, and while you wont always have the mana to make it happen, bringing this back constantly does represent a major problem for your opponent, whether youre behind or ahead
A creature or planeswalker on your opponent's side is gone just by casting 3 black mana, then you can turn around and exile this creature to get a Zombie token in return
5 Dig Through Time This is one of the best draw spells ever printed, letting you look at seven cards and take two of them, and it only costs two blue mana