Everything goes dark as the simulation starts to construct itself. Your senses dulled as the program begins, and your mind loosens. Memories of your life leaving you, and a new reality finding you. It's hazy at first, but the details eventually come forward. You're an adventurer, just an ordinary guy born to a poor family. Spending your days with ragtag groups as you delve into dungeons and search for treasure. You’ve lost plenty of companions to monster. The beasts fucking your friends as they transform into the same species of monster that was dominating them. But you’ve always had luck on your side, and always escaped unharmed.
You look around as the darkness fades, seeing a group of three other humans nearby. All of you standing at the entrance to some ancient ruins, motifs of snakes across the rows of pillars that lead to a closed stone door. From here, you can tell that the passage goes straight down. Deep into the earth where the rest of this dungeon continues.
"Alright, let’s get this shit opened and get our loot!"
A member of your squad says. A broad-shouldered man, shirtless and in short cloth pants. A strap is his only other piece of clothing, wrapped around his heavily muscled chest and keeping a sword in its sheath. The lot of you stepping forward as he brings his tree trunk arms to the doors and pushes. Straining himself with a groan before looking to the rest of you.
"Give me a hand!"
Deciding you're up for the task, you join this man and push forward. Feeling some progress... you're getting there... just a few more seconds and-. You feel the ground underneath you give way. The opening of the door triggering a trap as the four of you are helpless to the power of gravity. Your sight of the two in the back blocked as you fall past a stone wall, which then moves into a slope that quickly catches you and your companion. No injuries inflicted as you slam into the stone due to a strange liquid that coats the slope, yet you're still helpless as you tumble down until you hit flat ground once more. The two of you taking a moment to recover before standing, looking around your new environment. A passageway lit by torches and continuing in a straight line, with no end in sight.
"Shit... well. Nowhere to go but forward, aye?"
Your companion says with a laugh as he steps forward. You having no choice but to join him as you start to walk ahead. Traveling for minutes with no end in sight, is this passage endless? No, looking around you notice it's a slight slope down. You're going deeper into the earth, deeper into the unknown. Nervousness fills you but the fighter with you seems unphased. Undeterred as you watch in horror as the clueless man is quickly encircled by a monster that drops from the roof. A single grunt escaping him before he is coiled by this mysterious creature.
You take a step back as this monster appears. Looking it over to see what it is, the fighter fully obscured by this creature now. This strange serpent. Its lower half is exactly like an overgrown snake, a long tail covered in light blue scales. Current wrapped around your companion, and currently adjusting as you see quite a sight. A cloaca in view, a single large dick poking out from the opening. A throbbing pole, strikingly human that is repositioned as this serpent continues to coil around the man. Eventually the cock is out of sight and you can look at the rest of this monster. After its serpentine lower body, you see a humanoid torso. Muscular chest and bulky arms, all covered in a thick layer of those same light blue scales. Your eyes eventually look away from its masculine glory and to its head. Visage matching a snake, a cobra to be more precise. Skin in an almost hood shape as it connects to the torso, a forked tongue escaping its mouth, though there's still a human aspect to its look.
"Sssssstay there, human. I will get to you quick."
You gulp, recognising what this beast is now. A naga, snake lower half and humanoid upper half. A rare monster that makes their homes in dungeons and ruins, coiling around unsuspecting adventurers and-
Your heart drops as you hear the sound of grunts and groans. The naga putting into practise what you had just thought. Part of his tail moving backwards and forwards as the monster releases moans of pleasure. The human being pinned releasing similar sounds as the monster thrusts into him. His dick firmly planted in the barbarian’s ass as he gets to work.
You know how this ends. Naga's fuck their victims senseless, coating the captive’s interior then exterior with their sticky juices. Watching afterwards as the victim transforms due to the seed, becoming another naga enthralled by their captor. You need to do something, but you just can't. All you can manage to do is continue to watch this muscular naga thrust against this captive human. The monster hissing with delight as its groans become louder. Thrusts more intense until they reach their limit, a final hiss heard before there’s a flood of liquid. The serpent quickly uncoiling as you hear a loud thud. The human once more in view, on his back and in pure ecstasy. A pile of creamy white spunk leaking from his ass, the man still groaning and moaning as his meaty arms stroke his erect cock. His own climax reaching him soon after and painting his chest white.
The naga starts to stand over the man, rubbing his thick cock against the humans muscular abs. Pre leaking out, slowly building up to another flood as the serpent climaxes once more. Coating your companion entirely in cum, then backing off and watching.
You consider running at this point, but your legs just don't work. All you can do is watch as the human starts to make slight movements. His legs pressed tight against each other, until the flesh starts to combine. Forming a single long tail that is quickly overtaken by green scales. Extending up his body like a wave as his entire lower half is altered, dick emptying the last of his human seed before hiding in his cloaca. Emerging once more seconds after, thicker, longer. Filled with naga seed as your companion seems delighted. His torso inflating slightly as the scales reach it. Defining itself into an even stronger form. More muscles, bulkier arms. The fighter hissing with delight as the rest of him is soon overtaken. Face reforming into a snake like visage, features quickly matching that of a python as his forked tongue escapes with a hiss.
The new naga slithers off the ground and onto his converter. Pressing his manly torso against the other naga's own rugged body. Rubbing against each other as they join in a hug and embrace in a kiss. The former human's cock hiding in his cloaca as his master’s cock is revealed and erect once more. Finding itself at home in the opening, thrusting deep inside as the two men rub their bodies together and continue to be lost in embrace. Another flood of seed finding itself in the fighter, before the two part and stand side by side. Eyes locked on you.
"Usssse your new body, sssservant. Convert the human to our causssse."
Your former companion has clearly forgotten himself. Eagerly moving towards you as his dick sticks out once more. Slick with the other naga’s cum, and already leaking his own pre. You need to do something quick, or you'll become another naga.