(kinda Xover between "Salvation War" and "Amber Factory" from Pixiv)

Leilah pressed her lithe body against the cave wall. Just a moment before, she stepped into the meagre leftovers of a Baldrick again, and explosions sounded from everywhere.
"Males are so stupid", her Grandma Sheba used to say. Well, evidently the fact that she could gave a man an erection that would make keel him over from lack of blood had made her somewhat hybrist. Not an uncommon character error for a demoness! And now her body probably lied somewhere in a science lab on Earth, and to all her orifices to please man Bill Clinton had added an unwanted one with a .357, proving size doesn't matter. Bill Clinton, Succubus Slayer, of all! If there were some Destiny force above God and Satan, she must laugh her ass off now.

It sounded so simple. God and Satan agreeing that now after 2000 years the armageddon prophecy will come true, and mankind would queue for the big reaping. Such rotten timing. Only 100 years ago it would have gone more or less as planned. But mankind had advanced. To the point that they had weapons now that could show even a Baldrick demon the middle finger in form of 1 kg TNT equivalents. And now they even had the nerve to overrun Hell itself. Even hellfire was a candle flame in comparison to atomic bombs. Science had proven stronger than magic, especially given that magic didn't exist.

Somehow Leilah, who had no more physical strength than a human female, had to manage finding a commanding Earth force General, lull him with her shape projection, and overpower him with her pheromones. Damn cameras which could see through her deception! Damn gas masks which blocked off her pheromones! Damn the fact that she was only 100 years old, practically Succubus jailbait, her powers weak.

Delighted squeals came from around the corner. Leilah gripped her pistol (some unlucky Earth soldier probably had dropped it, she had picked it up for Satan may know what use it might be) firmer. Sqealing succubae should be a good sign. She stormed into the room...and froze with horror. Earth mechs, nothing but mechs! She fired a few rounds on the biggest hunk, but it was less than impressed. In a split second, it lashed out its tentacles and disarmed her. She squirmed and pedaled but his steely grip easily kept her in place. She looked down and was shocked with horror again. Many of her sisters, encased in some glassy stuff, like as if they were an exhibition piece! And what were the mechs doing to them?

Leilah found out immediately. The claws lowered her in a bassin which slowly filled with a gooey substance. Robotic appendages forcibly squirmed into the places that were reserved for human appendages. "Nooo..." she wanted to scream but the machine sprayed some pseudo-cum into her throat in a mockery of human-succubus love. Leilah gulped.

And then her body and her fate was sealed. Maybe an Earth woman could have made a last ditch escape attempt as the claws retracted from the hardening goo, but being a Succubus, the vibrating button the mech had attached to her clit had brought her to orgasm in seconds. Leilah enjoyed with limbs going limp until it was too late. The goo now was hard as glass and made any movement impossible. She wanted to move! She wanted to twitch and scream as the robocock pulsated in her vagina, bringing her to orgasm again and again.

Leilah didn't really notice anymore when two generals entered the scene of cum. "Why don't we just kill them? They are so frail we even don't need to waste a bullet!" "Always bad karma to kill a woman, even if she's a demoness. They are neutralized now, anyway. Do you think we can hand them out as playthings to our men?" "A bit risky. Their little cunts still ooze pheromones by the ton. So either we have to invent an airlock for dicks..." Both generals cackled hysterically at the thought. "...or we should check the effects with some volunteers...we'll have enough of those."
"Mind if I volunteer for a moment?" General A dropped his trousers. Of course Leilahs glassy prison had been designed to allow easy access to her strategic spots. Her permanent orgasmic throbs held the generals dick in a vice grip. "Oh yeah, baby, milk me...RHA-LOVELY! No, I don't feel any adverse effects now...Wanna try her throat, just in case?" General B did as suggested and quickly fired a cumshot into Leilahs gills. "In any case...RHA-LOVELY!...we don't have to rush our decision. They aren't going anywhere after all..."

They repacked their weapons and exited still laughing, leaving Leilah captured in orgasmic heaven. Since she was immortal (well, modulo unwanted additional holes) as a demoness, heaven would be truely eternal...

The End