Hurrah, I can be useful to this project now! Okay, so if I have to use a different character as a base, I'll make sure to change their appearance as much as possible.
Edit: 
Finished huhwhat`s sheet.
This is my character's sprite so I get to be super nitpicky about it :>
First of all. I'm not really familiar with FE style portraits, but is it possible to change the color of the outline? It looks really weird around the purple parts of the robe.
Aside from that, the head seems a bit vertically stretched. If you compare it to the portraits of
FE8's playable characters, my head looks somewhat taller than the others. Or maybe it's just my imagination, idk. If you could make the expression a bit more friendly looking, I'd appreciate that too, because it looks somewhat :smug: to me and I'm not sure that really fits too much.
Finally, shouldn't there be shading where the skin connects with the bangs at the bottom right of my face? The transition from the skin color to the dark brown doesn't look very smooth and it seems kinda awkward. Not sure if I'm explaining this right.