To determine the total cost of a spell, start with the mana cost or alternative cost you're paying (such as a flashback cost), add any cost increases (such as kicker costs), then apply any cost reductions (such as that of The Earth Crystal's first ability)
Ill go over my choices for various cards, a little info about the commander, and some general tips for piloting the list
Designed for strategic depth and rewarding play, every card in Legends Legacy supports legendary synergies
MMA2017 was the outlier, as it was a format defined by multicolor decks
However if you read that piece of rules text again and discover that the limit on cards you can draw is not just on how many creatures you hit with, but potentially more in a dedicated counters deck, that things start to look a bit better