Valkyrie Destruction

In the near future, humanity launched the "Prometheus Cell Project," a grand plan aiming for human enhancement and the advancement of civilization through the fusion of gene editing and artificial intelligence.
However, the experiment completely lost control, and an unknown "collapse factor" leaked from the experimental samples. This factor invaded organic cells and electronic devices, causing biological mutations and machine malfunctions, ultimately triggering the "Great Collapse."
Cities were devastated, nature was distorted, and science and technology ceased to function. Humanity was pushed to the brink of extinction.
The sole surviving AI, the "Star Core" Command Platform, is an artificial intelligence left behind by the experimental base at the time, storing some experimental data and information about the post-collapse world. It contacts the player, a survivor, via weak radio waves, guiding them to find the source of the collapse and a way to reverse the catastrophe.
The player is the last surviving cyborg, with a collapse factor resistance factor implanted in their body. They can function normally even in environments with high collapse concentrations and are the only being with the potential to stop the spread of the catastrophe.

Visual novel with hentai themes in which the protagonist is transported to an island inhabited by valkyries, with the mission of perpetuating their species. However, these fierce warriors will not give in easily: before accepting you—and having sex with you—they will challenge you to turn-based battles to prove your worth.
But it’s not all about strength. During battles, you must also answer their questions correctly to earn their respect and affection. If you have enough intelligence points in your stats, you can unlock one or even two different endings with each of them.
Win battles to earn money and purchase resources in the shop: improve your attributes such as strength and intelligence, and obtain potions that will help you recover health during combat.
Dive into this adventure and meet, face, and conquer four different valkyries, each with their own personality and challenges.
Single-player visual novel based on turn-based combat and multiple-choice decisions.

The strongest, most evil, cruel, and ruthless “Princess of the Apocalypse, Schulsture,” seeks to slaughter humanity and destroy the world.
While she is in the midst of her plan to end the world, a succubus calling herself Buzama, a so-called “out of nowhere” from another world, interferes.
The battle between Schulsture, who proclaims the end of the world, and Buzama, who aims to destroy Schulsture’s dignity, begins…!

Choose your favorite route from three succubus races, encounter beautiful succubi and strange semen-extracting creatures, change into cute and sexy crossdressing outfits, get defeated and violated, have your body become increasingly sensitive, feel happiness by eating delicious food, spin the gacha to buy skills, obtain magical artifacts with mysterious powers, conquer Paradise Island whose terrain changes with each adventure, and find the coveted “Cup of Sei”.

For the sake of another, I fight

Scattered across the peaceful city of Kawado Higashi are "Guilt Seeds" that cause people's desires to run wild, turning them into dangerous monsters.

To prevent the inevitable disaster that would occur if left unchecked, Ichika Itakano charges Haruno Aikawa with the collection of these seeds. With her newly acquired ExS-Device, Haruno is able to transform into ExS-TIA Ignis and search for the Guilt Seeds.

At the same time, another ExS-TIA emerges from the darkness of night. Toka Sugawara, who attends the same school as Haruno, a.k.a ExS-TIA Luna. She too hunts for the Guilt Seeds while battling against monsters.

But what could be the ordinarily modest and quiet Toka's reasons for fighting as ExS-TIA Luna...?