2021-03-19 You are never forced to activate mana abilities to pay costs, so if there is a mandatory additional mana cost (such as from Thalia, Guardian of Thraben), you can decline to activate mana abilities to pay for it and hence fail to cast the suspended card, leaving it in exile
Obviously we dont want everything staying in the yard, so well need recursion effects beyond our commanders ability
Making her a great storm commander
Ten lands is fatal with no other attackers, blockers or damage dealt
The first stage of the saga lets it tap for colorless mana
As I explained in the introduction, due to a lot of the Eldrazi creatures having the Devoid mechanic, they are colourless, so will benefit from this discount