At this point, your trade partner will likely be grateful that hes getting anything out of the cards that the vendor rejected at all
By adding Linvala, the Preserver and Evolutionary Leap to the deck after sideboarding, we are trying to win a battle in the skies
Given this green instant is also a Plummet, I think it just qualifies as a high quality sideboard card that you could always main deck in a pinch and not be too sad about
Killing two creatures is awesome and gives you card advantage, and it's pretty common that you'll run into both flyers and non-flyers as well, not really limiting your options as much as you might think at first
It costs 0 mana to play and has the ability to tap and sacrifice itself to add 3 mana of any single color to your mana pool
The majority of the best colorless cards MTG has are artifacts, such as tools, machines, or ancient relics