You are a "young" cultivator dwelling in the Mist Continent, you have now reached the age of 350, and finally reached the final tiers Nascent Soul realm of cultivation. Miraculously, you managed to avoid incubization, as you actively refrained from interacting with mamono beyond small conversations or a trading deal, as you did for the last couple centuries. Having demonic energy in your system will risk destroying your foundation forever, the very thought sending shivers down your spine ( An Incubus and a Mamono energy cycle is a method of stockpiling power, not actual cultivation, entailing stages of progress rather than mindlessly accumulating ). As much as you would like to settle down with a cute and loving mamono, that could come after you acheived immortality.
Avoidance of mamono does not imply absence of them. Many a mamono had incessantly proposed to you, and just as many tried to rape you, and just as intensely, you denied their advances at every turn, and for that you denied and in some cases, shamed them publicly if they got fiesty. Through some twist of fate, these mamono met. Angry and humiliated, they took this complaint, of the "cruel" "boy" playing hard to get, to one of Eros' emissaries ( a Houri ). When Eros herself received the complaint, the streak of sadism, an atavistic throwback to the far more ruthless state of the gods before the current Demon Lord, decided to administer her judgement directly.
Eros located you as you were busy gathering Thousand Star Netherites and Gleaming Faerie Aurum to forge a design gained from last night dream's inspiration, she charged a mighty curse, and hurled it at you, striking with a precision that would make Apollo green with envy. You shuddered as the curse rooted itself into you, expecting the worse, but you felt nothing. You sighed in relief, and continued with your gathering.
500 years later
You've done it! You reaches the Ascension realm of cultivation, and you only needed a bit more to reach Half-Immortal, then to Full Immortal. But you reached a bottleneck as well. It was at this time the seemingly benign curse reared it's ugly head, as you and the Golden Phoenix sect senior Yun Ling Fei ( she's human, of course ) planned to begin the "Dual Cultivation" ( If you know what I mean ( ͡° ͜ʖ ͡°) ) plan. You eagerly sought to begin this, as it would provide you the power for a breakthrough. The curse activated in entirety. This Dual Cultivation style requires a great love, fostered betwixt the Yin and Yang ( you and Ling Fei ). The love, so carefully nurtured, breaks down instantly, and in your despair, you visited Eros, not knowing it was her who cursed you. As you prostrated yourself before her, you feel a wicked aura fill the temple.
Eros reminded you of the time when you rejected the advances of the mamono, and revealed them to you, they having been hiding nearby. She offered you a choice: continue to search aimlessly for your Yin, never to pass Ascension and always filled with an agonizing void, or couple with all the mamono, and keep your power level, but become an Incubus and lose the ability to cultivate. You trembled at this ultimatum.
Will our brave MC finally succumb to the plague of mamono, or will he manage to obtain his Yin, even with Eros preventing him? Or... will he rage, rage, against her, against the heavens, just as the legend Meng Hao did?
WWYD?
Notes: Holy s__t, that was a long writ. Hope someone finds this and gives a juicy reply!