You should always play your Mirage core starter with Leona and Yone. Round them out with a Guardian like Braum or Nasus and then a warrior like Wukong. Level to 4 at stage 2-1.
Since we use Yone as our item holder for Daeja early on and Leona to hold items for Nunu we can further build into Guardians. Level to 6 at stage 3-2.