[flashback]
before the encounter, he was just flying around to check a bit some towns near Tokyo, he found at least 7 places that houses vampires, but the most interesting thing was that gargantuan graveyard that was some miles away from him, it released a big stench of death, and a great dark energy, so he got towards that direction.
When he arrived there he found many graves, too many, it seems numerous like stars and each one has a name and the data of his death, some were pretty decent, while others were exactly at the moment the virus attacked everyone, he walked forward, avoiding stumbling in these graves, until he found something interesting.
While he was walking towards the center, he found some bone spikes, but the bones weren't the size of a normal human, but they were ranging from half meter to 5, all of them were strong enough to damage him, then he got to the center, it was a flat place without obstacles, except for that rock that was used as a seat for that man, it was the seraph, and it got up and took his greatsword, readying himself for the fight.
[present]
seraph: I am the Death's Knight, and in the name of God, I will erase your existence!
then he rushed towards Xiao Qiangwei while using his greatsword like it was a normal sword, his movements were almost perfect, he was using all the disadvantages of using an heavy sword, if it wasn't that he was in a Lower Realm, he would think that it was the Prison God Sirius' Tome, Xiao Qiangwei used 'Burning Heart' and created claws made of his ice to block the hit.
The ice cracked a bit but it was repaired some instants later, under Xiao Qiangwei's feet a big crater was created, while Xiao Qiangwei himself trembled a bit, the seraph raised an eyebrow and jumped a bit away
seraph: I congratulate with you, human. Being able to block my heavy sword, only demons and other seraph could hope to do it, what's your name?
Xiao Qiangwei: This one is surnamed Xiao and named Qiangwei.
Seraph: mh, I will remember it, and I will make a majestic grave for you. Now fight for your survival!
then Xiao Qiangwei rushed at him and tried to slash at the Death's Knight, some hits were blocked from the sword while others slashed the armor, until suddenly he used his golden flames and the seraph backed away, then Xiao Qiangwei moved the flames and used one of his profound skills
Xiao Qiangwei: 'Burning Sun Rupture'!
then he launched a big stream of golden flames to the seraph, who used his sword to take the hit, and blocking it succesfully.
Then the seraph rushed again while Xiao Qiangwei dismissed his left hand's ice claws and used 'Purgatory' with 'Falling Moon Sinking Star' and 'Colossal Fist of the King', and punched the seraph's armor after dodging a slash from him.
The hit was incredibly strong and made several cracks through the bone armor, while the seraph flew some dozen of meters away, when he balanced himself, he was surprised from the strength of the punch, while Xiao Qiangwei already prepared to use the 'second step' of his profound art
Xiao Qiangwei: Evil God's Domain: Ice
then the graveyard flashed a bit before it was completely frozen and snow started falling, the seraph was surprised from the sudden change and from the coldness.
then a white blur came towards him and Xiao Qiangwei hit him with a kick precisely where the armor cracked, creating more cracks and making the seraph stumbled of some feets before he regained balance and raised his sword in air.
At that moment, some bone spikes got through his feet, injuring Xiao Qiangwei and surprising him
Xiao Qiangwei: tsk...
then he curved backwards to dodge another spike that would go through his head if he was a moment slower. And then he got out his feet from the bone spikes and started flying in air, right now the seraph and Xiao Qiangwei stared at each other until Xiao Qiangwei felt something behind him and turned, to see a giant dragon made of uncountable human bones and with glowing red eyes.
seraph: My beast! Attack him!
then the bone dragon roared and fly at Xiao Qiangwei, but he just snorted and used a profound skill
Xiao Qiangwei: You little fucker! 'Destroying Sky Decimating Earth!'
Then the dragon got hit from a gargantuan explosion that destroyed the upper half of the dragon, killing it and making bones falling from the sky, the seraph watched with shock at what happened right now, while Xiao was breathing heavily due to the energy consumed for the attack, and then slowly descended, and started looking at each other again.
seraph: human... no, Fallen God... you proved to be as strong as us seraphs, and I admire your strength, but you are a threat to everyone in this world, if I am going to die, I hope that you could grant me a wish...
Xiao Qiangwei: talk, angel.
seraph: I wish you to make a grave for my body right at the center of this graveyard and put my title of Death's Knight over it, I don't have a name so I can use that title instead, I hope you can grant the wish of this seraph.
Xiao Qiangwei: yes, I will. After this, I will burn the body with my divine flames, and put the ashes in a pot made of the strongest ice this realm has ever seen, and the grave will be made with the same material.
Then the seraph nodded and rushed at Xiao Qiangwei with his sword in air, but before he could strike, he seen a gargantuan azure dragon roaring at him, paralyzing the seraph for some seconds, it was the Dragon God Domain of Xiao Qiangwei, and at that right moment he activated another profound skill
Xiao Qiangwei: 'Blazing Sunray'!
and a little ray made of the hottest divine flames he could muster right now and shot it at the seraph chest, penetrating the already cracked armor and trepassing his chest, killing him.
Then Xiao Qiangwei walked towards the dying body of the seraph, and said
Xiao Qiangwei: I will mantain my promise, you just need to rest.
Then he closed the seraph's eyes and the armor fell piece after piece, until the body of the young man he was before remained. Then he burned the body to ashes and created an ice pot and put the ashes inside it, and closed the pot, then he made an hole near where the seraph was sitting before the fight and put the pot inside the hole and covered it with dirt, after that, he created a giant cross made of ice phoenix's ice and manipulated it to write the words.
"There is the Death Knight's ashes, a seraph in human body, who bravely fought until he couldn't move anymore"
Xiao Qiangwei: *sigh* It's a shame I couldn't capture him alive... He was too strong to be captured.
Then he looked around and just noticed the density of the dark energy and whistled
Xiao Qiangwei: this place is a fucking heaven for me! Time to cultivate!
then he put himself in lotus pose and started cultivating 24/7 while recovering from the fight.