1. Bonus EXP, unless you can grind for levels
2. Nerf the cavaliers into their Tellius incarnations due to them being a little on the OP side thanks to access to two weapons and the highest movement in the game. To add on to this separate the Mages (thunder, wind, fire) and Knights (Axe, Lance, axe and maybe Bows).
3. Let us choose what weapon to A/S rank. For example You can have a Hero with either an A in axes and B in Swords, or an B in axes and A with Swords.
4. Bring back the magic triangle, it wasn't that good but it was still interesting.
5. Bring back Tellius Bases
6. Bring back the older classes that only made an appearance in one game like Soldiers, Halberdiers, Summoners, Griffon riders, etc.
7. Have unique pallets for characters in certain classes. For example A Mercenary that has a red and brown color scheme should have the same color scheme if they are a Bow knight or Hero.