Avatar of Woe becomes an incredibly cheap and effective threat after some milling gets done
Typal decks should consider Raise the Palisade, which is a way to help push damage through and reset the board, without interfering with your own deployment
There are a lot of ways you can improve on these
8 Strongest: Impervious Greatwurm A Green Wurm, this 16/16 costs three green mana and seven colorless mana
(2021-06-18) If you cast a card "without paying its mana cost," you can't choose to cast it for any alternative costs
To determine a spell's total cost, start with the mana cost (or an alternative cost if another card's effect allows you to pay one instead), add any cost increases (such as multikicker), then apply any cost reductions