Unfortunately, he is cockblocked

First thing first, he probably should subdue her, using the Ownership would do the trick, plus, he is going to interrogate her later and perhaps some payback while he is at it.

Before Issei could write on her, he sense a presence and heard a flap of a wings

"What do we have here?" Issei heard a voice from above. a promptly cursed at the bad timing.

"Shit,"

Looking above him, Issei saw another Fallen Angel, this time instead of a BDSM bitch, it's a gothic loli in a frilly dress. She lands down with elegance and stare at her fallen(pun unintended) comrade.

"Hmmm, Raynare got defeated by a human? No, you're a magician, aren't you? I sense magic here." The blond Fallen Angel said as she then look at Issei with a smile on her face.

"Ummm, who are you?" Issei asked, hoping to stall for time to come up with a plan.

"Oh, well I'm glad you ask," she made a bowing gesture by lifting her skirt slightly like one of those fancy girls, "I am the great Fallen angel Mittelt."

She does a twirl with the greeting too,

"This girl is kinda full of herself,"

Though Issei isn't fooled, he has to do something quick,

Luckily, he had gathered a lot of mana, so he could use some spells,

"Though I have to be smart, she most likely know that I am not someone to be underestimated considering I beat Yuuma,"

"Unfortunately for you, I won't let you kill her" She summoned those light spears, and Issei does not let her use it as he prepares a magic circle and aims.

"Oh, a spell?" Mittelt prepares to dodge, but instead Issei shot it below the ground, a wind spell was cast as it hid the ground, causing dust to rise.

"Hey!" Mittelt cough "That was playing dirty,"

Now having a good distraction, Issei had the chance too-