You should always play your Mirage core starter with Leona and Yone. Round them out with a Guardian like Nasus or Braum and then a second Swiftshot like Twitch or Ezreal. Level to 4 at stage 2-1.
At level 6 you want to slowroll to 3 star Yone. Since you need a stalling frontline for Yone to stack his Rageblade - you can play something like 4 Guardians at level 6. Level to 6 at stage 3-2.