Alliance - Selesnya Conclave

Choose a green/white legendary creature card
from your draft pool that shares a color with your
commander, the chosen creature starts the game
in the command zone as a lieutenant to your
commander and adds to your deck's color identity
(You may add green and white cards to your deck.)
A Lieutenant may be cast from the command
zone once per game. Once a Lieutenant leaves
the command zone it cannot be placed back in
the command zone when it changes zones.