I updated my old Dynast mod for CoE3. This is a mod designed to have powerful hero units that level up with xp, starting as solid front-line commanders and ending as end-game monsters that can steamroll armies.

Changes from the CoE3 version:
Mastery rituals were totally redone, so I had to simplify advancement and get a bit clever to fit in the constraints of the "power" command only going to level 5. Now you can always do Intensive Training at the cost of 200 gold and a whole year of AP. As before, leveling up for only 50 gold and 1 AP is possible when hp is at a certain level (using the fact that each star of experience gives +1 max hp).
All heroes are set to have no item slots until they are max level. A little sad, but otherwise getting a +hp item is gamebreaking as you pass it from hero to hero and level them all to max.

https://drive.google.com/file/d/1c5XboDI9R6eXmkktm57UEEOV0OC2Uw3l/view?usp=sharing

The Dynast claims to have the mandate of heaven to rule over Elysium and create a line of succession for descendants to reign in perpetuity. The Dynast is a powerful force on the battlefield and attracts other mighty heroes to pledge their allegiance.

Each Dynastic Hero has the potential to develop their skills to legendary heights. This can be done at minimum expense upon attaining a new rank of experience. Impatient heroes can supplement the advancement of their prowess through intensive training, though at high cost.

The rule of the Dynast is declared at watch towers and guard towers, and a recruitment center is established at each controlled tower. Each tower has a small chance of attracting a new hero each turn.

The Dynast's bodyguards have been trained to take a support role, and will never crowd Dynastic Heroes out of the front rank. Elite bodyguards with magical elemental weaponry can be recruited occasionally.

Abilities:
Dynastic Heroes can level up with enough experience or money. The Level Up option becomes available whenever the unit gains the title 'Experienced'.
Control watch towers and guard towers to attract Dynastic Heroes.