Shinsei Kourin Dacryon - Runa ~Daseibo Tanjou~ 2

At sunset, by the river, the Dacryons transform to fight a swarm of insect-like creatures known as "fallen babies."
— "At that moment... we could not even imagine what would happen to us..."
Being surrounded by enemies, the Dacryons become covered in sticky saliva, which immobilizes them. The tentacles slide over their bodies, penetrating every orifice before forcefully invading them, mercilessly breaking their limits. Their bodies begin to change, and soon all three find themselves sprawled on the ground, trembling, bleary-eyed, and covered in seed. A cursed symbol appears on their bellies, pulsating, awakening an uncontrollable, consuming lust.
“And then... the inevitable moment came.” Now, trapped in a world of fallen angels and monsters, Dakrion comes face to face with the one behind it all - the Holy Virgin of Vice.