Reborn: Ulquiorra In DxD World

Sona went back to the human world after staying here in the underworld in a few days. Sona was glad that the engagement was broke. She didn't want her friend to marry a man she didn't like.

Ulquiorra didn't follow her as he didn't received any order from Serafall. He just stay in the mansion with nothing to do except when Serafall called him to practice their speech.

"I'm Magical Girl Levi-tan... " Serafall said as she waved the pink wand in her hand.

"And I'm... " Ulquiorra didn't managed to finish his words as someone knock on the door.

Knock!! Knock!!

Serafall stop what she was doing. She turned her head towards the door and said, "Come in"

A servant entered the room and bow respectfully before saying, "Serafall-sama a fallen angel enter the Kuoh town. Rias Gremory's peerage was currently battling the said fallen angel."

"What?!!" Serafall exclaimed in a loud voice. She immediately regain her posture and said, "Continue.. "

"According to the intel we got Rias Gremory is not an opponent to this fallen angel as this fallen angel is Kokobiel a Cadre rank fallen angel." The servant stop for a moment before she added, "also, Sona-sama is helping her."

Then another servant entered the room and bow at Serafall.

"and you.. " Serafall looked at the servant who just came.

"Serafall-sama, Maou Lucifer is calling you for a meeting" The servant said.

Serafall nodded and said, "Okay, both of you can go now"

The servants once again bow their head before they quietly leave the room.

Serafall silently ponder what she should do. She then heard Ulquiorra's voice.

"Should I go to Sona" Ulquiorra said as he looked at Serafall.

"Whoa!! What a nice idea Ulqi-tan, for now you will become So-tan''s protector" Serafall said as she raised her wand up in the air.

"First, I will go to the meeting" Serafall said before she looked at Ulquiorra and said, "Protect Sona in my place Ulqi-tan"

Serafall then bid her farewell to Ulquiorra before she left the mansion.

Ulquiorra looked at her disappearing figure. After she was gone, he opened a garganta that lead will lead him to human world.

...

In Kuoh Academy.

Kuoh Academy became the battlefield in the battle between Kokabiel and Rias Gremory's peerage.

Currently, Sona and her peerage form a barrier that cover the whole academy. Sona, Tsubaki, and the rest pour their magic power in barrier to maintain it.

Sona was worried about her friend because her friend was not fighting an ordinary fallen angel. That fallen angel was none other than Kokabiel, a Cadre class fallen angel, a fallen angel that possesses five pair of wings.

She eventually shook her head and choose to believe in her friend. Their task is not to fight against Kokabiel but to maintain this barrier. They put a barrier because they don't want to involve normal people in this fight and also the leakage of the powerful magic power can harm those normal people in the town.

'There's so many bad things that happened in these past few months' Sona complained. The first thing that happened was also about fallen angel but those fallen angel were ordinary fallen angel that possesses one pair of wings. The second thing that happens was about Riser, Rias ex-fiance. Luckily, Issei managed to beat Riser. Then this high rank fallen angel appeared here in Kuoh town.

Even though she wasn't directly involved or she wasn't the one taking care of the trouble. It still gives her an headache.

Hooooooomh!!

Suddenly, they heard a strange sound behind their back. All of them simultaneously turned their heads and saw something strange.

"What is that?!" Saji exclaimed in a loud voice.

"...I don't know" Sona replied as her brows knit together.

They saw the space behind them became distorted and it slowly opened like a mouth of a monster. It revealed a pitch black space.

"Now of all things!!" Tsubaki gritted her teeth. They wouldn't be able to maintain the barrier if an enemy appear beside them.

Then, they heard a footsteps coming from inside the pitch black space.

"I heard something" Saji said when he heard the sounds.

"W-what's that?" Momo said.

"A footstep?" Tsubaki said a she furrowed her brows.

Sona frown and said, "Something's coming".

All of them put up their guard as the sound was getting nearer and nearer.

After of few seconds of waiting a man walked out of the black space.

"Ah!! It's you!!" Saji exclaimed when he saw the man.

Sona breath a sighed of relief when she saw who walked out of the black space. She lifted up her head and asked, "What are you doing here Ulquiorra?"

That's right. Ulquiorra was the one who came out of the black space also called garganta.

He looked at her and said, "The same as last time".

"Onee-sama" Sona muttered in a low voice as she press her finger in her temple. She felt warm inside her as her sister even send Ulquiorra to protect her.

"What's that?" Saji asked while pointing at the garganta behind Ulquiorra.

This sudden question of Saji piqued the interest of the Sona and the rest.

Ulquiorra looked at Saji and said, "Garganta"

"Garganta? What's that?" Saji muttered confusedly.

"Garganta? That's the first time I heard that term." Sona muttered in a low voice while looking at the garganta behind Ulquiorra.

Ulquiorra ignore them and he instead observed the battle inside the barrier. Even though there's a barrier he still could clearly seen what's hapoening inside.

After a few seconds  he opened his mouth and said, "They're losing. They don't have a chance to win this fight."

"What?!!" Sona exclaimed, "They are losing"

"Yes, they are currently being beaten by that fallen angel." Ulquiorra said to her.

"C-can't you do something" Ruruko said.

Ulquiorra glance at her before saying, "My duty is to protect Sona not them... "

"but... " Ulquiorra slowly lifted up his arm. He then waved it towards the barrier.

Boom!!

"I can eliminate anyone who is threat to her existence."