The barrier however, did not shatter immediately when the Spartan punched it. It did not look like it particularly liked being punch, probably because it was being protected outside the dungeon it was not as strong as normal, but it was not so flimsey to get destroyed with a single punch.
The miasma meanwhile seemed to corrode everything in its path, with the ability to even corrode energy barriers in seconds or less. It would keep approaching them and coming after them. And with Blackhearts help with firing at it from the outside after the Spartan had damaged it, the barrier was then finally broken.
But, that was not the end of it's attempts as it went after those two still. When Jeff TRIED to grab Lilith, before she could accept the action of her own free will or react in any other way she wanted as a character with her own will, tendrils of miasma shot inbetween them to cut them off. They would then attempt to go around and totally engulf Jeff as they came from all sides. The power of the miasma seemed to focus on this attack, and it would almost certainly completely errode and damage his armor as the miasma had concentrated which meant its power and ability would increase. It would come at all sides, move to block escape routes, and then come at him from every direction to eat through his armor and shields. When he tried to run, they would all focus on that route and make it even worse for him.
Meanwhile, to the trio that just arrived, Rivian only saw as the actions happened. He had no idea if that armored guy was even alive after that attack, but with that armor there could be a slim chance that the person inside was alive. Because of that, Rivian decided to bet on that chance and summoned his Blood Katana. He was not aware of what this miasma did exactly, but based on what he saw from the battle already, included shell casings from bullets that had been degraded, it seemed to have some sort of degenerative ability like the Demon King. In that case, Rivian's Blood Katana...or rather, the sword that was summoned from his power which he did not know the true name of, Murasame, was pulled out. Because Murasame, known as the Blood Katana to everyone as no one knew its true identity, was made from Rivian's Blood, it had the benefit of Adaptability, which meant he and Rivian could adapt to the miasma.
And Rivian knew if the miasma was a defense mechanism, then his power could get it to dispel. And so, he charged in and cut through the miasma to save Jeff, or whatever remained of him.
The moment he did, the miasma swarmed Rivian and attacked him. Rivian fell to the ground on one knee, but was enduring the pain. It was not just inside his body, he felt Adaptability working incredibly hard for something. It had never made him feel pain before, but he knew the feeling beside the pain. He felt it every time the scientists cut him open and transplanted tissue or an entire Organ into him.
And then finally, the miasma dissipated all at once as if it was never there. The dungeon stopped sending out monsters, and those still out turned to black ash. Rivian sighed with relief. "I guess this means that my ability will...work...to..."
He suddenly realized that his outer layer of clothes did not have adaptability, and were torn to shreds. Thankfully he had been wearing a jacket, so his shirt was fine, but the others were totally degraded and fell off other then his shoes. He pulled his shirt down skillfully and with extreme speed, but...
Actually, something strange happened. Rivian's clothes began to reform onto Rivian. Until he was totally back to normal, and could stop pulling his shirt down. Everything was totally restored.
"I put in tech and programmed it to regenerate. Since I heard the Demon King had some sort of degrading or degeneration powers, I thought it would be good to have clothes that not only served as armor, but would regenerate themselves but...it looks like the degeneration power is stronger then I thought. They couldn't keep up. So...so...we should probably be careful".
Rivian said that as he looked towards the door. After he took several deep breaths, and calmed down his embarrassment, he took a few steps forward.
"So, is everyone ready?"