DxD: Multiversal Therapist

*BOOOOMMMM!!!*

She had started a hard offensive the moment she saw Ray cross that gate. Ray told Azrael to stay at the margin and flickered away from Tsunade's fist.
Each one destroyed a massive portion of the land, she hadn't been fighting seriously in that battle against the Re-Estize Kingdom; It was evident.

"Do you even know why you fight?" Ray commented, easily dodging as she gave chase in the forest.

"..."

Tsunade didn't say a word, her amber eyes focused on her target, she kicked the ground and flickered. Her movements were ridiculous, worthy of a kunoichi, clearly an expert in martial arts from Ray's point of view, with incredible speed and also astonishing strength behind each strike. 

Ray jumped high in the air, his arms crossed. She was strong, but there hadn't been anything that he considered threatening so far.

Her strength, although devastating, was far from able to match his.

*WHOOSH!*

She flickered and arrived above him, placing both her thumb and index in a circle in front of her mouth.

<Fire Style: Fireball Jutsu!>

A gigantic fireball lightened up the night and shot towards Ray so didn't do so much as budge. Even if she had cast an entire sky of flames against him, that wouldn't be able to do anything against his complete fire resistance.

He extended his hand forward and swallowed that flame in front of her shocked eyes.
'So fire is not it… should have guessed' she smirked and watched the fire of his fist transform in colour.

<Sun Burst!>

!!!

*BOOOOOOMMMM!!!!*

A technique she had seen dozens of times, but never felt. A gargantuan explosion collapsed the forest with strength equivalent to what she considered a 'Tailed Beast Bomb'. The view alone was majestic, especially during the stillness of the night. 

<Water Style: Great Waterfall Jutsu!>

<Earth Style: Stone Wall!>

To protect herself from the explosion she had to use two techniques. Still, both crumbled in the might of the sun's energy. Tsunade's body was blasted away and burned.

Ray noticed how her injuries seemingly regenerated at ridiculous speeds, although it wasn't the same as his curse of the sarcophagus, Tsunade seemed to have her own means.
The Sun God felt her regeneration kick in and receded, giving her time to recover. A cloud of dense hot vapour had formed as a conclusion of the clash.

"Stop your useless struggle, you're strong, but–" he began with bravado but quickly felt her regain her footing and start yet another jutsu with a snicker.
Angry at her insistence, Ray blinked and grasped Tsunade by the neck amidst the smoke, only for her body to turn into a dissolving water clone.

!!!

The real Tsunade jumped off the smoke, towards his right. Ray saw that coming, but when the silhouette cleared it wasn't just one Tsunade... they were two. A real and a clone, both camouflaged beneath the same energy readings.

*BAANGGG!!*

She knew his advantage and fooled his senses, from the very start, from the moment he got that power, she had been annoyed at Energy Records, and therefore started planning countermeasures against it. It was the job of a shinobi to counter every path of warfare.

"Don't underestimate me, kiddo!"

The first Tsunade smashed forth, he blocked with both his arms.

*BOOOOOMMMM!!*

The sheer force destroyed the ground below his feet, failed to even bruise him, but effectively locked him in place. The second Tsunade slid down and swiped a kick down his feet.

"Ugh!"

Ray lost balance and was about to fall, but his body levitated mid-air, ignoring gravity; a chance the first Tsunade took to grasp him before he could fly away from her counter. 

"Where do you think you're going?!"

She grasped his waist and performed a suplex that shattered the world.

*BOOOOOOOOOOOOMMMMMM!!!*

Debris blasted everywhere creating an earthquake that surely enough would reach the Baharut Empire's camp. Azrael who witnessed the fight from the skies gasped at Tsunade's brutality. She realised how much she had underestimated the Sannin who by now she could tell still wasn't fighting with everything. But in any case, neither was her Lord.

"That kinda hurt," Ray groaned, spitting a rock that just entered his mouth, in the middle of a gigantic crater, undamaged but dirty.

He did a quick pirouette to grasp Tsunade, the real one and smash her head against the ground in vendetta. The sannin smirked; another clone of hers popped up from the ground to pin both his feet while the real one countered his pirouette with skilful taijutsu to smash him once again towards the ground returning his manoeuvre with splendid colours.

*BOOOOMMMM!!*

The boy was awed, not at her strength, not at her persistence, but by the capacity she had to counter everything he had to offer.
It was the difference in experience.

Both real and clone restrained Ray, he groaned and pushed her to get up, but Tsunade did some hand signs for the first time and touched his chest with them.

"What are you!–"

<Fuinjutsu Trap!>

A weird symbol materialised in the ground below and Ray found himself unable to move. Tsunade wasn't joking. She sealed him.

"I have watched you fight from the start. Your strategies, techniques… I know them all, Ray. You may be a god, but you're a god I know very well~" her voice sounded confident, but she was panting and her skin was hot and feverish.

A high human she may be, but the overuse of sun energy was starting to take a toll.

'I still can't use chakra. This may be a tyrannical form of energy. But I can't use it recurrently' she concluded and pressed Ray further down, straddling him and going on top.

She looked at the skies where Azrael levitated without making a move and smiled.
"Stay right there, don't do a thing…"

"..."

Azrael certainly didn't make a move, although she wanted to, but it was her master who had ordered her to not intervene no matter what. Nevertheless, she also believed in him. 

"Do you think you have won?" Azrael asked her, Tsunade ignored it until Ray asked the same question.

"Do you think... you have won?".

A shocking revelation that made her frown since he wasn't supposed to be able to even speak in this seal.

"You're indeed a God".

Just to be sure, she created two more seals and plastered them on Ray's body, the whole area's ground shone in a complex seal pattern.

"... still easier than I thought, strong indeed... but you lack a lot of combat experience. If you had come to me intending to kill me, things would have ended quite differently".
She traced the boy's lips, recalling the dreams she had every night from the moment they met, never had he looked so vulnerable.

"..."

Ray didn't say a word and she laughed, realising that the seal was indeed working as he couldn't move regardless of how much physical strength he put into it, it was as if the seal had disconnected his brain from the rest of his body.

Admittedly, this was the only way she thought she could ever restrain him as he was nearly an invincible existence, a nightmare to any foe.

Immensely difficult to injure or bruise. If bruised he would quickly regenerate faster than the eye could blink, even if he lost a limb it would grow back, if his heart got smashed it wouldn't matter, if his entire body was erased from existence, it would just pop back up. 
There was no god to thank as he was already a god, but she rejoiced Ray wasn't her enemy.

He just couldn't be killed.

'But as everything that exists, he can be sealed' she naively thought.

"Come on, say something~ you were so arrogant before, telling me to decide... to make a choice you know I can't bear".

She caressed his body, still infatuated, still feeling those minor electrical currents with the slightest touch of her fingers.

Tsunade's first move was to open his trousers and grasp his member directly. Without asking questions, without asking for opinions.

As much as he looked forward to it, Ray had other priorities. 
<Blazing Springs Ashes!>

"It is useless, this is Fuinjutsu (Sealing Jutsu), you won't be able to move–"

*BOOOMM!*

Ray's body exploded in blazing ashes, he disappeared in front of her and re-materialised not too far away as his body rejoined ash by ash. Just like Natural Pigmentation, Rubedo's power, he had adapted it into his own.

Tsunade gasped, initially thinking it was an illusion, she used a technique to dispel the illusion, but her next strike proved useless. His body dissolved like ash that charred her body upon contact. If he was ridiculous before... now he was untouchable.

Ray didn't even have to move.

She jumped back to the retreat and reconsidered her possibilities, but it all came to the same conclusion. Tsunade sighed and lifted her arms.

"I surrender…"

"…"

Her hands loosened and she smiled, "This fight is senseless... you can't defeat me, I can't defeat you".

"... I can't defeat you?~" Ray's brows twitched, the audacity of this woman was unprecedented. 

He sighed and dispelled Blazing Springs Ashes, opening his shirt and dropping it on the ground.

Tsunade stared at his toned-up abs and shining tattoo, resisting the urge to lick her lips.

"Come at me with everything you got, Tsunade".

The blonde smirked and discarded her own coat, remaining just in a tight grey shirt that accentuated her cleavage. 

*RUMBLE!!*

<Yin Seal: Release!>

The atmosphere tensed up, the crystal in Tsunade's head expanded and a tattoo started covering her whole body, starting from her forehead. 

"You just released a limiter or something?" Ray asked, amused. 

"You won't be laughing in a minute!"

*BOOOMMMM!!*

A mere kick, a simple move she performed to close up the distance, caused an impact so devastating that the forest behind her shattered, Azrael covered herself from the shockwave, gasping audibly. 

Ray put his arms together to block the fist... and the punch shattered his whole body in dozens of blazing pieces.

Tsunade's momentum was hardly stoppable, she managed to regain her footing half a mile away leaving nothing but destruction in her wake with her whole body shivering. 

"Ugh!!" She groaned, veins popped up on her skin and they were shining like the sun underneath, she felt like the inside of her body was inside a furnace. 

"I-It is the first time... I have used the sun energy stored... this is painful hehe~" Amidst the pain she smiled, staring at her work of art... a forest gone beyond redemption... and a fist so destructive that it managed to effortlessly shatter the tough skin of the very gods. 

It was at this time that she realised how much stronger she had grown in reality. There was simply no point in comparison.