At this moment, Gojo was barely keeping it stable. The spell, Thunder Step, costs a lot of mana to start up, but to keep moving, it only requires very little mana. But there was a catch. All things in life have a catch, and those problems are what the entire solution is built around.

The catch of life is death; being born is the moment your clock to death starts ticking. Getting a job also has a catch, and it is that your employer would eventually be making more money off your back than you do. Getting married comes with responsibility, and even eating means you have to shit something out eventually.

In the spell’s case, the higher the speed target he wanted to reach, the costlier the acceleration to get that point became, simply because the magnetic field would need far more energy. That would make it less and less usable and more of a waste.

To solve that problem, Gojo had to find a new loophole in Yog’s mana rules, and sadly, he had already found all of them. It was hard to optimize a spell that already reached its peak, even if he wanted to use it at much higher parameters. This just wasn’t the place, situation, or right environment to be creative and think clearly about discovering a new way of magic.

He would much rather do that research in a calm place, a desk in his castle with a cup of tea and a few capable hands to help him out. But sadly, he couldn’t afford that now and had to do it anyway.

Thinking out of the box, because everything in the box was already discovered, Gojo looked at the spell from a new angle while evading the Ice Brood Mother’s ice spears, poisonous fangs, and sharp threads.

Mana is a form of energy; it seeps into the body through the skin and can be used to cast spells. Right now, Gojo was forcefully sucking back the mana he used to cast magic when the effect is done to reduce the cost in a process called Mana Recycling, but even then... he was running low.

Conservation of energy was a thing, and if he is moving, then he has used some energy to generate that movement. In Gojo’s case, that form of energy he expanded was mana.

It didn’t matter how efficient his spells were or how good he was at recycling mana; he would eventually run out. There wasn’t a single spell that was a 100% efficient; such a thing was nothing but an illusion.

So, if he can’t reach 100% efficiency, he must work toward supplementing himself with more mana. To offset the loss, he had to go beyond 100% in his mana regeneration. If a car can’t drive 1000 kilometres on a full tank, no matter how optimized the engine is, then just make the fuel tank hold more. If he can’t do that, then why not refuel it mid-drive?

That was thinking outside of the box, and Gojo was good at it.

That is why and how he had now developed a new technique to accelerate his mana absorption by several folds. And unexpectedly, he could only thank Lucy and Yog for the inspiration. He could remember those two fighting in his office. Lucy was like usual, enjoying a full table of sweets when Yog showed up out of nowhere and landed right on top of the expensive cake.

At that time, Lucy, the glutton, was overeating to charge her divine magic, and Yog suggested sprinkling some honey on the cake to get a glazed cake with more sugar per serving. To challenge her, Lucy grabbed the pot of honey Yog pulled out of nowhere, and shoved her face in, taking a deep breath of the honey.

She didn’t want to just eat the sweets, she wanted to breathe them, to shove them deep into her lungs and body. Lucy was a goddess, so she was fine doing that, but Gojo couldn’t help but yell at her at the time.

Now, he was glad he saw that, because he was about to do the same.

He took a breath, and a deep one at that. Mana smelled like Yog... which made sense, considering that Yog is the goddess of magic and that her true body is the endless fabric of mana itself. So, in a sense, Gojo was now breathing Yog herself into his body.

He could sense mana seeping into his body through his skin, so what if he did the same, but from the inside? His lungs, the surface area inside them was far larger than his skin could ever be, since that was how he breathed. The idea itself seemed so outrageous that it might just work.

Can he breathe mana through his lungs? He can try. It might burn his lungs, but does he have a choice? He has other choices. He could try using wild magic again, but he had just blown a bomb at Entropy’s face, so it wouldn’t make sense for him to come crawling back to use her magic. No matter what, he won’t be the one giving up first.

With an even deeper breath than before, the veins on his face and neck bulged, and his lungs were set ablaze. He could feel it, a rush of mana flooding through his veins. But he could also feel and see her, Yog, taking form inside him.

For a moment, he thought she was going to block him from doing that, but then, he felt the opposite. She shoved more mana down his lungs and forced it to seep through into his blood. Yog was a sucker for magical development and advancement, and she won’t stand in anyone’s path, as long as they won’t destroy the universe.

Gojo’s body accelerated even further, breaking the sound barrier several more times as he had more mana to spare and fuel a stronger version of Thunder Step.

As his body moved faster than Mach three, the Ice Brood Mother’s eyes lost track of him, and he was moving too fast for her to keep up with. To her, he felt like an annoying mosquito flying around her head, too fast to catch.

Far above, still sitting with Entropy to negotiate, Yog smiled. "That’s it, you’re getting the hang of it."

Entropy stared at her. "That brat Gojo? Even if he is to be Cain’s vessel, aren’t you giving him too much favor? Any other wizards would’ve been long since killed by you."

Yog laughed. "Listen, I suck whoever I want, and it’ll make more sense later on. Many things are still locked beyond forbidden knowledge." She looked down at her feet, and could see Gojo fighting the Ice Brood Mother in Limbo. "Come on, show me what you can do, Cain."

"Cain? You’re crazy." Entropy sighed, and Yog shrugged. "Sanity is overrated; all the best people are crazy."

Back down, Gojo was finally faster. But that was just the start of their fight, and the outer shell of it at that.