The reason is because, to help separate Equipment from Auras, we made the choice to only allow players to equip artifacts to their own creatures
Deco is sharp, I love the blue and pink of the boxes and key art from the line
Tarkir: DragonstormPlay Booster Box contents
When you pay for encore, you exile the card and create tokens equal to the number of opponents you have and then attack them if able, and the tokens are sacrificed during the next end step
You'll be better off pairing Swarm Intelligence with something like Talrand or Voracious Reader to turn all those spells into damage, but even without either of them, Swarm Intelligence provides multiplicative value to every instant or sorcery cast
It does a lot of what you get from red - the ability to easily kill off small annoying critters