Decks that are hyper lean, like Murktide, Hammer, and Cascade-based decks are all vulnerable to Spell Pierce because they are using so much of their mana every turn from the start of the game that it is genuinely difficult to not find an acceptable use for Spell Pierce
There are also some interesting surprises among the new offerings, like a crossover promotion with the board game Disney Villainous that could be of particular interest to those who enjoy both games
The flexibility of what color of mana to spend to cast it is the icing on the cake
Uthros might not be an artifact, but its part of the Planet cycle in the main set, and that means it gets better when you put on charge counters
They dont let you cast a big spell for free or give you extra turns, but they do the dirty work that is necessary in Commander decks they make your mana way better
Here are the Japanese cards that were also revealed: