Artifacts like Urzas Sylex, Nevinyrrals Disk, or Oblivion Stone warp opponents playstyles around the threat of mutually assured destruction and certainly have their place in Commander, and in the case of Sylex, tossing an extra two mana during activation to Call the Gatewatch might be just what you need to break parity following extinction
Ive won a few games by locking down remaining opponents with Boggart Auntie plus either Fodder Launch or Warren Weirding on loop from the graveyard
Having an instant-speed fight effect is extremely valuable to some decks, allowing you to wreak havoc in combat
Run 3-5 instants that handle creatures, artifacts, or enchantments
No catches, no benefits for other players, just a nice, clean card draw