So a food for thought about a potential Fire Emblem character when he comes to Heroes:
You know how Shadows of Valentia doesn't let any of your units use axes despite said weapon being in the game (only the enemy units use it)? Because of this, it seems like we won't be having any SoV characters in Heroes that will use axes, right?
I wouldn't necessarily say that. There is one SoV character who I think will be an axe unit. Who? Atlas!
"But Eru, he's a villager. Neither his default class nor his secondary classes let him use axes in his game!"
But you do know that being a woodcutter is one of his most defining characteristics, right? As a man from a mountain village, that's his main job. He talks about this in a few of his base conversations.
And what does woodcutting involve in a medieval setting like Fire Emblem? Chopping wood! Also, look at Atlas's build. He definitely looks like the type that could easily carry an axe for that sort of thing. All those things said, I think it would make the most sense for Atlas to be an Axe unit when he's added into Heroes.
So what axe would he wield? SoV doesn't have any particular axes that stand out beyond the Shadow Axe, but Atlas doesn't seem like the kind of guy that would use it.
I think he'll likely wield an original axe for his debut in Heroes. Perhaps it could be a completely new axe called the "Woodcutter Axe" that would grant some kind of special effects. More likely, I think it'll probably be a more basic axe. The Brave Axe or the Slaying Axe are the two most plausible, though I hope he has the Slaying Axe as his default weapon since that would give him instant access to a competitively-viable axe thanks to weapon refinement.
Honestly, the thought of Atlas being the only SoV unit to use an axe in Fire Emblem Heroes makes him one of most wanted characters to be added in Fire Emblem Heroes (as well as the fact I actually like him as a character and think he's underrated because of his lack of supports), though seeing how he's one of the more unpopular SoV characters, we're probably not getting Atlas for quite a while.