This makes Altar the perfect pseudo-recursion, with the bonus of synergizing with token doublers like Anointed Procession and ETB effects like Impact Tremors
There'll also be 25 Background cards, meaning there's an enormous number of possible combinations to try out
You can get a decently powered flying creature and remove an opponents best card at instant speed
If you're outside of commander color identity rules, any instant or sorcery becomes a mere which is almost nothing with a Sol Ring, Ashnod's Altar, or Palladium Myr sitting around
Personally, I'm in the camp that believes you'll want to end up playing some number of both cards in most Red decks
The stack now looks like this: Hidden Strings (Copy), Hidden Strings (Original)