Guide to Get Other Rituals
The way to gain new ritual is usually either by:
- Upgrading an existing unit necromancer => Lich.
- Getting access to new units (with rituals or citadel upgrades or by conquering special location).
- ‘Borrowing’ units from other factions (enslaving/charming enemy commanders with spells is a great way to expand your options).
Rituals are the only way to gain other rituals in the base game.
Now… With mods you can.
The monster can grow into a new form through other means… Such as through hp or age.
By assigning a higher ritual power level to the new form, and making sure the rituals for that level are tagged as “free”, you could potentially acquire new rituals that way.
You should be able to use the recruitment window for this, “upgrading” the unit by replacing it with a new version, much like how dwarven upgrades work.