I've been playing the game and it's really fun. Despite being F2P, I've gotten some of the best units in my arsenal ( Hector, Ike, Celica, Takumi, Bridal Lyn, Ephraim, Eirika, Ephraim, Nowi, and Lucina )
My favorite build is my Hector. He has Pivot to zoom around, Distant Counter for obvious reasons, Threaten Defense to lower nearby foes' defense, and Renewal to keep himself in check, and Bonfire to add +20 damage.