Tiamat

As his 'battle' with Sesshōin Kiara came to an end, Shirou took a breath of relief.

Sesshōin Kiara, the woman who put the word '****' in therapist, was the most dangerous of the bunch.

Any interaction with her, especially the sexual kind had a risk of d*ath or worse, so with her down, Shirou felt a little less like a lamb to the slaughter.

As if mocking him, the sea grew restless, waves rising in an unnatural crescendo. The horizon bulged as if the ocean itself were inhaling, preparing for a colossal exhale. A wall of water, a tsunami, barreled towards the beach, consuming everything in its path.

Shirou's eyes widened, his heart racing as he realized who was next in line.

He didn't dodge or tried to defend. Instead, Shirou took a deep breath, bracing for the inevitable. The wall of water smashed into him, sending him tumbling into the vastness of the ocean. Yet, instead of the cold, suffocating embrace of the sea, he found himself floating in a strange, serene underwater realm.

The pressure was absent, and he could move and breathe without effort. The world around him was bathed in an ethereal blue light, the sound of the waves now muffled into a gentle symphony.

Aquatic life flitted by him, curious and unfazed by the sudden intrusion of a human in their domain. Coral formations grew into elaborate structures that stretched as far as he could see.

Then their she was, Tiamat, Beast of Regression, Goddess of womb and salt water, in her full glory.

A woman with a body ideal for birthing and nurturing, long pale blue hair that flowed like the sea currents, and a set of large green horns that curled back like the waves of the ocean. Her eyes, gleaming with a love that was anything but maternal.

"I'm sorry, if I kept you waiting, Mother," Shirou spoke, his voice unaffected by sea. Tiamat's eyes widened in pleasure at his words, a knowing smile playing on her lips.

"Not at all, my dearest child" she purred, her voice resonating through the water, "The anticipation has only made me more eager for your sweet embrace."

Her hair moved like kelp as she approached him. The sheer size of her was intimidating, her breasts larger than his skull, her waist thin yet wide hips promising a fertile harvest.

Her legs, powerful and graceful, propelled her closer to Shirou with each kick. Her hips swayed mesmerizingly, as if the sea itself danced around her.

Shirou felt a mix of excitement and arousal. He knew what was expected of him, what she was here for, but he couldn't wait to give it to her.

Her eyes locked onto his, filled with a hunger that was as ancient as the sea itself. Tiamat's vast form enveloped him, her breasts pressing against his chest as she drew closer. Her mouth found his, her kiss salty and demanding, her tongue exploring the contours of his mouth like a creature of the deep seeking prey. Shirou couldn't help but respond, his own hands finding the soft, curvy landscape of her body, feeling the power coiled within.

Her legs wrapped around his waist, drawing him closer, and he could feel the heat of her core against his thighs.

Shirou didn't need a second invitation. He pushed himself against her, feeling the softness of her flesh yield to his firmness. He didn't miss the way her pupils dilated as he entered her, her body accepting him as if he were the one that ocean tides had been calling for eons.

Her moan was like the distant rumble of the ocean floor, deep and resonant, sending waves of pleasure through him. He began to move, his hips rocking back and forth in a rhythm that matched the gentle sway of the sea currents.

Their bodies became a dance of lust, each movement a silent promise of more to come. Her legs tightened around him as she pushed back, urging him deeper, her inner walls clenching around him like a fist.

Shirou could feel the power of Tiamat's embrace, the way she seemed to envelop him entirely. It was as if he was being drowned in a sea of pleasure, each thrust sending shockwaves through his body.

"Mother, I'm feeling a bit thirsty from earlier, may I...?" Shirou's voice trailed off, his gaze flickering down to her chest.

Tiamat chuckled, a sound that bubbled up from the depths of the ocean. She reached for the top of his head and gently guided it down to her heaving chest, "Drink as much as you want."

Shirou felt the warmth of her bosom against his lips, and then the sweetness of her milk filled his mouth as he latched onto one of her nipples.

Her milk was like nectar of the gods, thick and sweet, with a hint of salt from the ocean she called home. He suckled greedily, feeling the tension in her body build with each draw.

Her hands caressed his hair, holding him close, The sensation of her flesh against his was intoxicating, each suckle sending jolts of pleasure to his groin.

Shirou could feel the tension in Tiamat's body growing, her breaths coming faster and her hips moving more urgently against him.

Her milk was a potent elixir, filling him more OD (life ****) than even the best potion made by modern mages. Each swallow of her heavenly nectar sent a pulse of power through his veins, his body responding to the call of the primal instincts she stirred within him.

He felt himself growing harder, more insatiable with each taste, his movements becoming more urgent as continued pounding into her.

Tiamat's moans grew louder, echoing through the current as she met him thrust for thrust.

Shirou's mind swam with pleasure, each sensation amplified by her divine essence. Her nails dug into his back, leaving trails of white-hot pain that only fueled his desire. Her legs tightened around him, her entire body quivering as she approached climax.

The pressure built within him, his every muscle straining as he felt the precipice of release approaching. He thrust deeper, harder, the friction sending sparks of pleasure through both of them.

Tiamat's eyes rolled back, her head thrown back in an arch of pure ecstasy.

"Aaaaaahhhhhhhhhhhhhhhhhhhh..." Her moans grew to a crescendo, the sound echoing through the aquatic chamber like the roar of a thousand waves.

Shirou felt her body tighten around him, her walls clamping down in a vice-like grip as she reached the peak of pleasure. He could feel her inner muscles spasming, gripping him as if trying to pull him deeper still. The warmth of her climax washed over him, mingling with the brine of the ocean as she filled the water around them with her release.

He couldn't hold back any longer. Shirou buried himself to the hilt within Tiamat. The **** of his orgasm was like the eruption of a volcano, hot and explosive, filling the goddess of wombs' womb with his seed.

Her body pulsed around him, He could feel her milking his balls, her inner walls squeezing and releasing in a rhythm that matched the beat of his heart. He groaned, his eyes squeezed shut, lost in the intensity of the moment. The water around them grew warm.

When Shirou opened his eyes, he found Tiamat smiling down at him, her eyes glazed over with pleasure. He knew she wasn't done yet. He had to satisfy her fully, to pump her full of cum till she looked ready to burst with his offspring.

With a grin that mirrored her own, he leaned in and kissed her, his tongue delving deep into her mouth as his hands explored the soft, yielding flesh of her breasts. Her moan of satisfaction was his cue to begin again.

Round 2 was followed by Round 3, then 4, and so on, as Shirou tirelessly worked to satisfy Tiamat's insatiable hunger. Each time he thought he had reached her limit, she would only pull him deeper, her body begging for more.

It was as if he was trying to fill the ocean with his seed, Eventually, he managed to succeed.

How long it took? He had no idea, he long lost the concept of time.