With enough auras and equipment spells attached to the right commander, it can be easy to eventually inflict 21 commander damage to your opponents to win the game
If it's a permanent spell, the copy gains haste and "At the beginning of the end step, sacrifice this permanent." (A copy of a permanent spell becomes a token.) Creature - Beast Demon Color tag templates(None) Nightscape Familiar Blue spells and red spells you cast cost less to cast
Whats interesting, though, is that outside of a few cards that can fish instants and sorceries out of the graveyard, blue struggles with casting these cards again and again
For example, I recently built a version of Aang, at the Crossroads, where the entire game plan was to resolve it and then copy it repeatedly to keep retriggering its ETB ability
Sensei's Divining Top, which taps to draw a card and puts itself on top of the library