(Valerie's P.O.V.) (Starting at the Same time as Rias's Fight)
Valerie was cutting down fallen angels like butter. She had a scarlet longsword in hand. It was a family heirloom. It sucks the blood from those it cuts and stores the samples for later use. In short, a very useful weapon to have with her ability.
10 minutes into the engagement, she found herself free of approaching enemies. Taking time to review the battlefield, she found what she saw pretty interesting.
On one side of the battlefield, she saw Ingvild engaging the Midgard serpent with her trident. It was a pretty safe battle all things considered. Ingvild could tame and kill the beast at any time. Hell, she probably would by the end of the battle. Valerie imagined that she would be requested to mould the serpent into a familiar If Ingvild liked it enough. Basically, realign its loyalty to them. Then, there was Rias, who had gone back to helping her brother contain the damage after completing her fight. Michael had decided to get involved in the fight and was fighting both Loki and Kokabiel. He didn't look all that tired, but that was likely because this whole fight was a ruse to signal peace to their factions. Azazel was fighting the descendant of Cu Chulainn who had taken his arm off earlier. With the element of surprise taken away, it was a much more even fight. That spear was much too powerful for that faction to have. On another part of the battlefield, Serefall could be seen battling Fenrir. She normally wouldn't be powerful enough to do so, but Azazel had taken to giving her a prototype replica of Absolute Demise, a Longinus Sacred Gear that takes the form of a sentient ice doll. By working in Tandem with the ice doll, Serefall was making headway. The problem was that the doll was unstable and wouldn't last much longer. Lastly, Sona's peerage (who had been on standby in another part of the building), Vali, and the two exorcists from earlier could be seen working together to take on Skoll and Hati. She was honestly feeling a little left out.
She had spent the majority of her time cutting through enemies while collecting blood samples of all the combatants with her sword. Due to this, she appeared the most erratic in her movements on the battlefield. While her allies had a rough idea of what she was doing, her enemies just thought she was a freak drunk on slaughtering their soldiers.
Suddenly, there was a loud crash near her kicking up a large dust cloud. Before it could clear though, a large muscular figure burst through and sent his fist in her direction. Surprised, Valerie barely managed to side step it and back up to regain her bearings. When she had gotten some distance, she quickly saw who her attacker was, but he had changed since the last time she saw her.
"Well now! Look who we have here. The friend of the bitch who crippled my leader!" He exclaimed as he slowly started walking toward her. His skin had taken on a red hue and his eyes had started glowing a bright white. Plumes of steam could be seen billowing out of his mouth with every breath. His form was also larger than before. This must be the Heracles family's inherited ability to power up when enraged. It was basically an anger fueled boosted gear inherited through blood.
Demigod families were like that. They inherited an ability similar to the pillar ability of the devils from their Demigod ancestor. In exchange, they are not eligible to receive sacred gears. That must be one of the reasons Cao Cao can lead the faction. He may be a descendant of a hero, but he doesn't have any demigod blood. He's completely human, hence the sacred gear. He's the perfect embodiment of their ideals.
"Good day hulking sir. I am indeed the friend of the woman who crippled your master; I honestly wish I was the friend of the woman who killed your master, but that is a title I will gain another day. I am a little confused though. I thought Cao Cao's hound was the one over there wielding the red spear?" She remarked sarcastically.
Another known fact about the Heracles bloodline was that their rationality decreased proportionately to their increase in strength. According to a remark made by Zeus, it's the price for mortals with diluted blood using the power of the gods. Essentially, all Demigod bloodlines have fatal flaws like this. Most of those families try to keep their weaknesses hidden, but the Heracles family's weakness is too obvious to ever keep hidden. This man was clearly already boosted up to a significant degree. She was surprised he was able to be patient enough to do so before engaging her.
"Aren't we funny. We'll just see how funny you are when I put your head on a pike!" He said as he charged toward her. In response, she once again side stepped his blow and slashed her sword creating a much smaller would than she intended. It seemed like strength wasn't the only thing that was boosted.
"Your weak attacks mean nothing to me!" a maddening smile rose on his face as the cut quickly closed.
"We'll see about that." She said, her eyes narrowed in observation of the interesting specimen in front of her. She needed more samples of his blood before offing him. Her preferred method of execution wouldn't exactly leave working specimens after all. She may be the nicest vampire one would ever meet, but she was still a vampire, the antithesis of the fallen angels. While they may be light-based masochists, vampires were darkness-based sadists.
Quickly, he kept rushing at her with semi-precise movements trying to tag her. Every time he missed, she would make small wounds on his body and they would proceed to heal. The thing he didn't notice was that every time she made those cuts, small amounts of energy were entering the wounds.
"What's wrong? You can't cut me with your pathetic sword!?" He roared with a mocking grin. As good as she was said to be, his body was already invincible. These little paper cuts were nothing in the grand scheme of things.
"I'm just testing the water. You may not have noticed, but despite how close you've been, I'm still untouched." She smiled brightly.
*Roar* He let out a resounding roar as his body continued to bulk up. Then, he once again charged at her. This time though, it made contact; specifically, his fist slammed into her chest. With the blow, her body flew through multiple ranks of soldiers before she managed to stop her momentum with her sword. She could feel a few ribs fracture, though she could already feel them regenerating. Being a demon vampire had its perks. Silently, the sword shifted into a scarlet lance.
"See that Bitch! It only took one punch and that's what happened! Anything you do to me is pointless, while I" he paused as his breaths became more labored, the veins around his eyes bulged, and his form resumed growing "just need to hit you a few more times to kill you!"
In another moment, he was once again upon her. This time though, his fist met the tip of her lance, which ripped much deeper into his skin and thus deposited much more energy. It's not something he would have normally attempted, but his mind was almost lost to him at this point. In exchange for high-ultimate class strength as a human, his mind was pushing himself beyond what it could handle. Actually, it was pushing it beyond what his body could handle as well. As strong as the Heracles bloodline was, it would never do that. It's a built-in limitation the original imposed on his bloodline following his ascension to godhood. The problem in this case though, was his opponent.
As the ruler of the principle of life and a vampire experienced with dealing with empowered bloodlines, Valerie was one of the worst opponents Heracles could face. While she couldn't kill him, she could make his life hell in the long term by turning his bloodline into a weakness. Over the course of the battle, she had injected multiple doses of her energy into the man, which she could control remotely. Those pieces of energy eventually accumulated and went about removing the limiters on his power while binding it even more heavily to his Psyche. Basically, less power is gained for higher bursts of anger and that power could accumulate indefinitely. It made the power harder to use in the long run and if it was used too much, like in this case, his body would start to crumble under the strain.
Already, she could sense an increasing amount of internal hemorrhaging from various points on his body. The body can't regenerate if it's too strained to do so. If he didn't stop now, then he was going to die.
"Ack! What's happening to me!" He barely stuttered out in his madness. While he was starting to realize a problem, his body still charged at his prey, who kept evading while meeting his fist with her lance.
This was the primary reason she switched to her lance at this point. His mind was so degraded that it became almost too easy to do so. Strong though his defenses may be, she could channel the tiniest bit of her master's power at the lance's tip and pierce it.
"It's a shame, as strong as you are, you're still weak. Cao Cao is an even bigger failure than I thought, choosing you as his bitch." She snidely remarked. This one though was the last straw. Power began to build up in him faster than she would have thought possible. Expecting the outcome, she commanded her power to begin dissipating through his open orifices. It had done its job. No need to make it easier for them to find out what happened to him or analyze the power that did it.
With that, his power officially entered Satan Class. The waves of power and the distorted sound waves produced from his fraying lungs flooded the area, alerting all the combatants to his rising power. The thing they found interesting were the clear sounds of tendons snapping, one of his eyes popping like a balloon, and blood seeping from every pore in his body. It was ghastly.
With this scene, Cu Chulainn and Azazel stopped they're fight for a moment.
*Whistle * "who would have thought the girl would be so vicious." Azazel commented with a slightly stiff smile.
Cu knew this was bad, this wasn't supposed to happen to Heracles. His power had never been this volatile before.
'It must be that blond girl. No time though, I have to get us out of here. Cao Cao was taken down a long time ago, so I guess it's my call.' With that thought done, he quickly assumed a sprinting pose and disappeared. Azazel may be more skilled than he was, but speed was his game and he was very good at it.
An instant later, he appeared in front of Heracles and crushed a small marble. Space began twisting around them and within seconds, they were gone.
His last thought before he disappeared was 'Man calming him down's going to be a nightmare.'
With both gone, Valerie and Azazel sighed.
"Well, that was a bit of fun. What happened to him anyways?" Azazel asked, his researcher mode spinning in full drive as he tried to process what could have happened.
"I simply amplified his own bloodline and removed the limiter. Nothing special" She stated simply as her lance reverted to sword form.
"Ouch" Azazel winced. He knew how volatile their bloodline was. To do what she just did would be a nightmare for him. They likely wouldn't be seeing him for a long time. It honestly might be a good bargaining chip though. The hero faction would need her help to correct the issue; that, or they could go to a god with the ability to correct the problem. That wasn't likely though as they had created quite a name for themselves as troublemakers.
"I think we've done most of the work needed doing. I'll head back to Rias and work with her to contain the damage." Azazel nodded with his classic smile. He was very satisfied with her display of power. His own fight would be a great prop for the boys back home. He needed to show that there was a viable threat. This would be the best way to do so. To support that effort, he made sure to hold back and not hurt Cu too much. While the match appeared even, Cu really was no match for him without the element of surprise. The boys back home wouldn't know that though.