Battle at Dragon Wall

As Battle at Dragon Wall enters the battlefield, choose Jeskai Way or Mardu Horde.
Jeskai Way -- At the beginning of your upkeep, draw three cards. Then discard a card.
Mardu Horde -- At the beginning of your upkeep, creatures you control gain double strike, vigilance, and trample until end of turn.
"Horrors beyond words..."-Sarkhan Vol