Auntie Blyte, Bad Influence The +1/+1 counters stack up by the same amount of damage you took, so the ultra-rare flying on a red card with no drawback becomes really important and quickly makes a lethal threat out of Auntie Blyte, Bad Influence
The death trigger for your insects is odd, but if you run mainly creatures and lands like many green decks, Zask makes mill two look a lot like draw two. #20
As a general rule of thumb, you want somewhere between 33 and 42 lands in a Commander deck
It also combos well with another card on this list, Pyrohemia, turning every one point of damage into a +1/+1 counter
Island #254 (Kaladesh) by Yeong-Hao Han This may be the very basic land that triggered my fascination with foil basic lands
If you miss your third land drop, you'll have 3 mana on turn 3