So far, I think use Vale City’s level up system for this type of game will be a good idea (obviously a lot faster because I wanna make a more fire emblem like game). Also I thought it will be cool to make enemies a little more than just a simple distraction for the experience so I decided I will give them droppable food or money. I want to make different character portraits too, for every 5 levels of the playable characters and 10 for the enemies.
In more TRPG related stuff I want to (basically) knock off a lot of fire emblem stuff such as Fire emblem 4 base/main castle, max level 30 system, promotion and skills ; Fire emblem 10 skill learn system (actually more like fire emblem 9) ; Fire emblem 2/Echoes magic; and a really nerf version of fire emblem fates hidden weapons.
I will expand this as much as I possible can, for example I will make the dismounted units get a slightly stat bonus for their movement lost