Regardless, the ring is overtuned, but I guess thats to be expected given that Wizards of the Coast made a whole marketing campaign around opening it
Grim Monolith earns its spot among the best mana rocks in MTG for decks that know exactly what they want to do with a sudden burst of colorless mana
Cinders are the difficult ones, but even they have fears to be exploited. Illustrated by Daren Bader Standard Not Legal Alchemy Not Legal Pioneer Not Legal Historic Not Legal Modern Legal Brawl Not Legal Legacy Legal Comp
It also means something like Tamiyo, Inquisitive Student won't appear here
Soul-Guide Lantern is especially effective against the Oops
There's an argument to be made that using Vivi as intended can result in long, drawn-out games of Commander where your opponents can get easily frustrated, but the strength of Vivi lies in his versatility