There is one problem for him though....

His magic sucked...

THough that ain't accurate, Issei thought as he does another spell, he can do the magic circle properly and thanks to his Ownership, he understood every concept and be able to do every single magic spells in the book.

The problem is his mana capacity, it is pretty damn low. His fire is a mere wisp, his wind magic is just a simple breeze, and he can barely do any teleportation circles.

"If it ain't one its another," Issei sigh, well this is just one step back he concluded. There is probably a way he could overcome this, just need to find the right books.

Issei had talked to Sona about this, and she had basically stated that his mana capacity is 10 times lower than the average person, 10 times!!

Already that puts a damper on his enthusiasm of his magical capabilities, sure you can cast more efficiently with less mana cost if you do enough calculation but Issei haven't gotten to that stage yet.

He could mitigate this by using runes to store magic power, but still though, refilling it with just his own would still take too long.

So with a few brainstorming, and a few inspiration from playing a few boobs, Issei had found a few solutions.

The first is siphoning mana from other user's, basically gathering magical energy from other people, and depending on the person's mana, it may have a unique attribute.

While Issei could just make Rias and Sona give a portion of their energy every now and then, it feels like a bit too limiting to just keep relying on them, plus he should gather his own servants after this, though he would like to try a portion of their demonic energy and their servants.

The second option might be slightly better, Leylines.

What are leylines? Apparently they are the flow of energy from the earth, kind of like a blood vein, they gather more in places with religious or landmarks, like an old church.

The mana one could gather is immense, but gathering it and controlling may be harder, so it tends to require a lot of preparation.

Though Issei had a few ideas on how to gather the flowing leylines. So he ventures on the edge of town near the forest, close to the hills, Leylines are usually around place with nature and are concentrated on religious place.

"Somewhere around here is ok," He looks around to find a good spot,

"Let see if it work at all," The book thing help him come up with this idea, finding a convenient rock, he wrote down his name with an added extra.

Hyoudou Issei's Leyline

Immediately, just like before, something appeared in his mind, a string of energy he can see that is flowing around the land, a lot of em is flowing to the church though.

He tries to command it to flow to his hands, and it followed, his hand wrap around by the leylines energy

"This-" The amount in his hand is immense, 10, no a 1000 times what his mana cpaacity has.

It's overflowing, yet he is in control of it, he trully gain ownership of the leylines and it's magic.

"Let's test some magic," Now then, what could he try to use. Not fire since that may burn down the forest, how about wind?

As Issei goes to the calculation that he remembers from the book, a magic circle appeared, and then a gust of wind that is so strong that it had shattered through a dozen trees.

*Crash*

"Is, is that my power?" Issei look in awe at what he had just accomplish, trees fallen uproot from it's roots just by the wind magic he had cast.

"Well, that might answer my mana problems." since Leylines are around the world, he would technically never run out, it's not like he expected to fight or some enemies or something, but it ain't hurt to be prepared right?

Plus, he might learn or create a new type of magic for himself. Fufu, he can't wait for when he learn some sort of strippig magic, that might be useful

Meanwhile,

"Is the ritual ready yet?" Raynare asked one of the henchmen,

"Yes Raynare-sama, we are just waiting for the sacred wielder to come," the man said,

"Good, at least you humans have some uses," she walked out of the underground room and head outside, there she sees three Fallen Angels among the trees

"This is getting boring, isn't there anything interesting to do here." The blond Fallen said, her leg swinging above the branch.

"Raynare-sama is given us order, we should do it diligently, not like you who kept going to the stores," Kalwarner said.

"What, I can't have a good treat?"

As the argue, Raynare had made herself known and they greeted her.

"Where is that crazy priest anyway?" Rayanre asked

"Walking around the town again, hunting some devil followers." She simply answered

"Huff, he might attract the attention from he devils at this rate," Raynare sigh, that priest may be trouble than it worth. "Regardless, we might departed after the ritual and killing hat boy,"

"Hmmm, weren't you ordered to observe him?" Kalwarner asked, that boy she is referring to is the one Azazel said to simply keep an eye on.

"Well, he has a sacred gear and it seems he might be acquaintance with the devils, wouldn'that make him a threat." Raynare said,

"Should we deal with him then?" The man with a trench coat appeared, his Fallen wings shown, along with that manic grin that shows some bloodlust.

"No, I can deal with the boy myself" Raynare said confidently.

"So, how are you going to get that boy then," Kalwarner simply asked out of curiosity "You did say he might have interacted with the devils,"

"Huffu, I have a perfect method that would work on a boy as foolish as him." From what she observed, the brat is a pervert, and all she need is just a bait to kill him, and what better way than to use a pretty girl, especially someone as beautiful as him.