Unfortunately, their battleground is our wallet, which will be empty after purchasing one of these valuable ETBs
The only spells that can be cast for free that are legal in Historic are Mindbreak Trap and Archive Trap, and both cards require your opponents to have done a specific action in order to do so
Of course, introducing The Soul Stone to Magic immediately raised the question of if, how, and when the rest of the Infinity Stones would show up in MTG form
Any "as [this permanent] enters" or "[this permanent] enters with" abilities of the copied permanent will also work
To illustrate this, lets use a simple example: You are playing against a deck any deck which is popularly assumed to run at least two Parallel City, a Stadium that can limit your Bench
Mesmeric Orb Mill per Card: 4+ Mill per Mana: 2+ The actual best mill card however with such a short time to perform there is a good chance Glimpse and the like are better in this list