While the replacement effect and mana reduction effect offered by The Earth Crystal are interesting, its activated ability leaves something to be desired
Whenever one or more cards are put into exile from your hand or a spell or ability you control exiles one or more permanents from the battlefield, create a 1/1 white Spirit creature token with flying
Other than some small sideboard tweaks, I think the deck is excellent and would recommend it moving forward into Modern
The latter has a power and toughness equal to the number of +1/+1 counters on creatures you control
Sin, Unending* Sin comes in and takes away the sin of playing with all those counters, and magnifies them onto its flying, trampling self
Dont worry, that compartment is removable