I prefer Unicorn and it is more useful in combat and let's be honest there is no magic in this Lona plot I expected more magical creatures and I still hope we have some references to famous works that I expect Berserk (Fairies), Bloodborn (The Great Old Ones), Elder Scroll (Dragons) , Nioh (Yokais), Dark Soul (Armor), Demon's Souls (Weapons), Elder Ring (Gods), D&D (Unicorn) and Castlevania (Vampires) make specific references in specific locations.
his is the point that does not guarantee that to obtain a magical creature, a summonable beast, a sacrifice is not necessary and I have a problem accepting other than real healing abilities, a combat and magic build only on the succubus side or being reborn as a abomination the self-healing ability involving amulets and desecration and to correct this I thought of a summonable familiar that would act to correct imbalance in combat, but I consider it very unfair that Lona does not have her own mount or an invocation as a mage, her perfect "Control of and Knowledge in Mana" this would prove to Big Mama her talent for magic.
Note: Unicorn would be your standard and familiar invocation as a mount and assistant in matters involving healing, protection and transportation, but as I know that Lona will not, will not maintain her physical and mental purity, could be corrupted by various activities of lust, it is likely that her invocation and mount were corrupted by all this and became a Bicorn and demanded carnal favors from Lona in exchange for support and help, that would make a great quest.