It might be a good idea to grind the upcoming Tempest for Orbs to spend on the Winter’s Envoy Heroes.
Directly to you from Twitter:
The summoning focus with bonus allies for the new Tempest Trials: A Gift of Peace has begun! There are 3 Heroes from Fire Emblem Awakening in the 5★ Focus category. #FEHeroes pic.twitter.com/1g4nLWE8WY— Nintendo of America (@NintendoAmerica) December 22, 2017
…Wanna play? Buy a 3DS.
That being said, click on Fire Emblem Heroes for everything you need to know about the game. 😀