The dragon and it's "three heads" and why Viserion had to die

Real quick cause I don't feel like typing a whole ton on this.

Dany = pure fire

NK = Pure ice

Jon = Fire and Ice

It's a total balance of ice and fire. Now that Viserion died, Dany will want Jon to ride Rhaegal so he could be controlled and safer, just as Drogon was safer with Dany able to turn him in time to avoid being hit by the ice spear. The three riders will be one of fire, one of ice, and one of ice and fire.

Should be an epic battle when it does happen