Urtet isn't super powerful, and you can definitely get blown out by an overloaded Vandalblast, but I'm really happy that we now have a viable Five-Color Myr commander in the format
Fell Stinger Deploy the Fell Stinger with its deathly scorpion's sting, and you can exploit (sacrifice another creature,) to evoke its 2 cards for 2 life ability, which can target any player
Each Aura and Equipment that phases out attached to a permanent that's phasing out phases in with that permanent and is still attached to it
While theres a lot of synergy here, the cards are mostly strong independently, and the deck is designed to play a fair, interactive game that just happens to be able to gain infinite life with Urza and the Thopter Foundry / Sword of the Meek Combo, but mostly Urza, Oko, and Emry are all amazing standalone cards that require fairly different answers
That means if someone casts a ten-mana spell, they are going to be milling ten cards on their next untap step