So far, this restriction has limited the play of Coax from the Blind Eternities to Standard, and even in Standard it has been fairly fringe
The OG bloodsucker of Innistrad, Edgar Markov is as powerful as he is popular
Ideally, you want to fill your deck with cards that take advantage of this, cards like Zendikars Roil and Scute Swarm, and then just make sure you can keep drawing and playing land cards until you eventually overrun the board with obnoxiously strong beasts that can trample through your enemies
If damage that can't be prevented is dealt to Ironscale Hydra, the damage is dealt and you'll simultaneously put a +1/+1 counter on it, before the game checks for lethal damage
Deadly Rollick Free spells have always been and will always be absurdly good because they ignore the most basic balancing mechanism in Magic: To affect the board, you must spend mana
And since its colorless, it can be a boon for any Commander deck