Sexual magics!

"Could I do things like... I don't know... destroy a person's clothing, or make a girl cum just by a touch?" Issei asked Akeno, who blinked. He didn't bother whispering his thoughts to Akeno with Asia around, given they were already sexually involved. Asia blushed at the idea.

"...that's... unorthodox," she giggled. "And very like you, Issei. Yes, that might actually be effective in the battle ahead. Losing clothing in the middle of a fight can be quite jarring, especially if one is a woman. And I have yet to see anyone who can fight in the middle of having an orgasm."

"Um... but don't you value consent to sexual things, Master?" Asia asked Issei.

Issei considered that, before he said, "Normally, yes. I'm a pervert, but I'm generally against using Rias's powers on unwilling women. Same goes for any powers I might train for myself. However, I'm also usually against doing things like punching people in the face. Considering we're going into a fight, all the usual rules are suspended during said fight, while we have opponents trying to hurt us, while we are also trying to hurt them. At that point, almost everything is fair and on the table. Of course, there will be lines I won't cross, even in such scenarios," he promised Asia.

"...aright then..." she nodded, giving him a small smile. "...you're going to need a practice dummy though, aren't you?"

"Oh? You volunteering?" Akeno teased Asia, who flushed and nodded. "Well, that is sweet of you, but let's work on practicing Issei's magic control first. Don't want him accidentally peeling off some skin as well as clothing if this turns out to be something he has a strong aptitude in."

Issei paled, and nodded in agreement. Yeah, definitely better to practice on something other than a person. She walked off, then returned with a crate of vegetables like onions and potatoes. "What are those for?" he asked her.

"Well, hopefully dinner tonight, assuming you don't ruin them, but for now, practice! Start with the clothing destroying idea, and practice the concept by using only magic to try and peel the skins off these vegetables!" Akeno replied cheerfully.

Issei looked at them, and inquired, "Seriously? You just want me to save you some effort in assisting with preparing dinner, don't you? Cooking was on your chore list for today," he added dryly. As useful as Raynare was to have around, they agreed not to have her do every little thing. They didn't want anyone getting rusty when it came to self sufficience.

Akeno stuck out her tongue playfully. "You see me pawning off some work, I see two birds and a stone! Get to it! Unless you'd rather go to evasion training!"

"Quit holding that over my head!" Issei yelped, immediately getting started, much to Akeno's amusement.