Mechanically, its okay, making a creature unblockable for a turn
All you need to do is leave at least one modular creature alive to absorb all the incoming counters, and you can get upwards of twenty counters a turn cycle
Stone of Erech - While I dont think this is necessarily an upgrade on Soul-Guide Lantern or Relic of Progenitus, it does get points for shutting down creatures entering graveyards
: If you both own and control Urza, Lord Protector and an artifact named The Mightstone and Weakstone, exile them, then meld them into Urza, Planeswalker
It's an instant speed spell with three different modes, for the low mana value of four
I think this is a super fun and exciting bomb that can completely blow up a game, but its 8-mana cost dictates that itll only ever really see play in casual Commander pods