Zion of Olympus You said that witches use Semen to rejuvenate themselves instead of just feeding, wouldn't not be possible for them to become succubi if they become desperate enough or if they lose control of themselves while feeding of men? And if so, would they be stronger than the average woman if they do so?
-Yep, witches remain humans after the pact with a succubus. So they continue to age, but due to the lesser version of energy drain, that they receive from the pact, they can rejuvenate.
-The only way a female human (or elf) has to become a succubus is by summoning an Incubus and offering herself to him. She'll then become a lesser succubus without clan.
-The witches are not plagued by the endless hunger a succubus has. Succubi have this hunger due to have taken form in hell, and therefor inheriting the endless hunger that the Original Sin had, since the Scorching Hell is his "corpse". So, no, they don't lose control and can more easily disguise themselves and feed while in the cities. Lesser Succubus without clan inherit this by the corruption that the incubus inflicts upon them. PS: Succubus didn't develop illusion magic yet, in the bronze age, so they use witches as spies if necessary.
-What do you mean by stronger?
--If physically: No, not even succubi themselves are strong physically, the overwhelming majority of the succubi have the strength of an average female human. In fact, engaging the enemy with anything that it's not magic or a relic is looked down upon by the hierarchy, and the succubi who do this are ridiculed. That's why they develop extremely powerful magic and excel at temptation, if both fail, they are pretty much useless. The two exceptions to this rule are:
---Crimson blood clan: their curse made them stronger physically than the average male, but not by much.
---The faction Scarlet of the Hellish Clan: These are really strong, they have the strength of a Gorilla. And they live in constant war with the Azure Hellish that hates them, as they think they are a "stain" on their clan.
---These rare traits are not passed down through their pact.
--If Magically: Absolutely, they have much more magic and now knowledge that the succubus provided them. New destructive spells, knowledge, documents and secrets. The pact however, does NOT make them allies. The witch is not required to fight for them.