Highschool DXD: The Harbinger

Fuyuki, Japan,

On the roof of a local high school known as Homura high, one can see a girl wearing a red coat with twin tails and blue eyes looking around cautiously as if she would be suddenly attacked from out of nowhere, her worries were proven correct when a man wielding a blood red lance suddenly appeared out of nowhere on one of the water tanks and started to talk,

Soon enough, the girl was forced to run from the man as he proved to be superior to her, but the moment she jumped off the building, she was caught by an invisible man who took her to safety and deflected the lance of the man dressed in blue,

but all three of them were unaware of a young man with red hair watching their battle, neither were they aware that the most bizarre servant in history was watching everything unfolds in front of him from the same roof of the school on which the others were on,

'they are seriously going at it aren't they?, seriously, this is only the first night of the war and things are already heating up right Sakura?' the hidden servant said to his master through their link as the said girl was watching everything through his eyes,

'Rider, be careful, that spear is giving me a bad feeling' the girl said through their link, worried for her servant, but the said servant only smirked to himself and said,

'don't worry Sakura, there is literally nothing in this universe that can challenge me in any way' he said,

suddenly, the lancer stopped fighting the archer and turned towards the school building and disappeared where Ryner saw a student, run for his life, he then suddenly felt the panic that Sakura was feeling before she shouted through their connection,

'Nii-san save him if something happens to him I won't be able to forgive myself!!!'

Immediately, the monster of a man took off as he arrived at the boy's location in a single second, but it was still too late as he was already stabbed through the heart by the lancer, he could feel the despair from Sakura through his link, but before he could take action, he sensed the Archer arrive at the location accompanied by his master,

He watched as the girl continued to struggle to find a way to save him, he watched as she took out a red gem which had an impressive amount of power stored in it which she used to heal the boy, Shirou, but after she left Ryner found out the anomaly from the boy,

He had an artifact in his body, but not just any artifact, if what he was sensing from him was anything, then it was most likely a holy relic of the highest caliber, he watched as the artifact healed what the girl, Rin had neglected,

'Nii-san, is he okay?' Sakura's voice rang out in his head as he could feel her fragile state of mind,

'Yes, he is fine, for now anyway, but if what I am sensing is right then he will most likely be involved in the war somehow' he said as Sakura stayed silent before she spoke again,

'Is there any way to ensure his safety? I cannot lose him'

'well, it is possible for me to enhance his powers but it is not without risk, his body is not capable of withstanding even a single drop of my power without exploding from overload, unlike you or your sister, his body is not talented in terms of magecraft, all i can do for now is to arrange a secret guard for him who will make sure to protect him from the shadows' he said,

'.......do it' Sakura said,

Ryner shrugged before he focused his void power, immediately, a fissure appeared mid-air from which a gigantic mass of shadows emerged,

This was a voidwalker, one of the many creatures that were loyal servants of his legion, voidwalker was by nature intangible but were capable of manipulating the void to an extent, but there was another reason why Ryner chose a Voidwalker as the guard for Shirou,

They were the bane of anything that is undead, including Servants,

The Voidwalkers after being upgraded by Ryner were capable of completely absorbing and neutralizing souls of their targets and were completely immune to all forms of physical attacks and curses, the only way to harm them was through the use of Holy energy which was nonexistent in this universe,

Ryner commanded the VoidWalker to look after shirou and to save him if something happens, Sakura gave a sigh of relief, knowing that her newfound brother's summoned creature would without a doubt protect her crush,

'You better make me a big feast for this' Ryner said through his link as Sakura giggled,

ever since Ryner was trapped on Azaroth, he had not had a proper human meal for centuries, and Sakura's cooking was no joke either, this resulted in him becoming obsessed with her cooking, secretly he was already planning on a way to convince Sakura into coming with him back to his homeworld, he would even reluctantly take that kid Shirou with him if needed,

Just as he was about to get back to the Matou residence, he sensed a powerful aura behind him, an aura that was almost equal to that of a Hindu god from his old world that he had once had the fortune of meeting,

In front of him stood a man dressed in a biker jacket and casual black pants with golden hair and red eyes, his very presence spoke of power and arrogance, a disposition of a king,

Thus,

The King of Heros locked eyes with the King of Demons