Here a new system for souls that I have been thinking, after writing all of this I realized that this will affect the other races and probably should put this in the general theme but, oh well.
Separate the souls into four types, Tame Soul, Wild Soul, Pure Soul and Corrupted Soul
Tame Souls are from normal animals, they can be processing for cooking or trapped in gems for low tier rituals.
Wild Souls are from giant animals and most underground animals, they can be processing for cooking or trapped in gems for medium tier rituals.
Pure Souls are from sentient creatures, they can be processing for cooking or trapped in gems and they are used for most of your rituals
Corrupted Souls are from Megabeasts, Forgotten beast/Titan and HFS and can be trapped in gems for high tier rituals, they can't be eating but can be devour in the Temple of Sin for a stats buff.
Soul can either be "raw" that may disappear if you left them lying on the ground and can be used directly for rituals. "Processed" that are stored in barrels for food and need at least one other solid food to be prepared into meals. And "gem" that doesn't decompose and can be used in rituals and trade.
All Succubus receive a happy thought for eating souls, a buff in all learning skills and the possibility of becoming addicted to souls, Tame Souls having the lowest (3-5%?) and Corrupted Souls having the highest (50%?). When a Succubus become addicted to souls she will gain +250 in all body attributes, -250 in all soul attributes, except for Willpower and Kinesthetic Sense, and talented in one random combat skill and liar. She doesn't need food or sleep and will not claimed any room, when on a break she will seek and devour the soul of other sentient creatures that they catch sleeping. If you leave a Succubus devour to many souls she will become a random HFS unleashing FUN in your fortress.
All reactions that used souls have to be modified to accommodate to this system but a few reactions that I would like to specify are:
You can merge 5 Tame Souls into one Wild Soul and 5 Wild Souls into one Pure Soul in the Well of souls. You can also breaks one Corrupted Soul for 60 Tame Souls, 25 Wild Souls and 10 Pure Souls.
You can devour raw souls in the Temple of Sin for a stats buff but with a increase in the risk of addiction:
- Devour Tame Soul > 50 in a random body attribute
- Devour Wild Soul > 80 in a random body attribute
- Devour Pure Soul > 150 in all body attribute
- Devour Corrupted Soul > 350 in all body attribute
"Learn pheromones + entice" used one Corrupted soul.
The Temple of Fire has a new reaction called "Cleaning in Flames" that uses 10 Pure souls to remove addiction to souls, gives a permanent debuff in all attributes.
Summoning HFS only used one Corrupted Soul, they are pets that can't be trained for war or hunting and are always tame but they will devour the soul of any creature in a restraint or cage. You can make them like Plump Helmet Man for extra FUN.
This also gives a reason to go to the secret FUN for farming of Corrupt Souls or maybe you can create a means to trade prisoners and large amount of Pure Souls for Corrupt Souls only unlockable when you discover the secret FUN.
And finally I think the Megabeast Kennels should be a building only available for Succubus and Warlocks, fits more thematically, Succubus resurrect them with additional fire power and Warlocks with undead features.