cards rotating out of standard mtg Three-Year Rotation is Standard's Real Problem Untapped.gg - Popular Cards Rotating

Prosper fits perfectly alongside cards like Light Up the Stage or Jeska's Will to create a loop of extra cards and mana

Any existing effects or counters that raise, lower, or switch a creature's power and/or toughness continue to apply to the creature's new base power or toughness

Legendary Creature Enchantment - Horror Commander (CTRL to add secondary) Artifact Lithoform Engine , : Copy target activated or triggered ability you control

The downside is that the lands now enter the battlefield tapped so you don't get to use them immediately and Roiling Regrowth is worse to copy than Harrow, since Reverberate'ing Harrow nets you 2 extra lands while copying Roiling Regrowth only nets you 1 extra land

You don't have to reveal the cards in the face-down pile, no matter which zone they're put into