Total War Emblem battle in Fódlan ( Fire Emblem THX Total War medieval)

This is fanfiction of this story about England, France, and other kingdoms in Europe in history. Basically Edelgard's kingdom is like Rome, Dimtri's like the holy Empire or the German, and Claude uhhh maybe Poland or somewhere in the Eastern lands. Seriously Fódlan looks so like Europe.

In the year of 1180 in Fódlan. New Kingdoms began while some began a rivalry or conflict. King Y/n of Britannia who now became king while Kylip who is now King of Thermidor who is now king. The two kings began to war because of their father's death. It was then Fódlan's kingdoms must choose who is the one. After the events what will the two King's do after another war in Fódlan begins.