There is no such thing as an invincible aether formula.
There might be a bunch of formulas that have the word "invincible" in their names, like [Invincible Golden Body], [Invincible Hellfire Wheel] and [Invincible Iron Toe], but they were anything but.
All formulas still had an aether expression of some kind, and depending on the expression, certain advantages and weaknesses become evident.
Aether followed the rules of elemental balance, which meant that Iganti(fire) had an advantage over Aeroqi(air), Aeroqi beats Terraqi(earth), Terraqi beats Aquarii(water) and Aquarii beats Ignati. Caligos and Luxari counter-balanced each other, obviously, while Omni was just...there.
There was even more nuance in regards to the more unusual expressions like wood, lighting, poison, etcetera, but that gets complicated real fast.
It should also be noted that said advantages can be overcome through sheer gap power differences. Water may extinguish fire, but it doesn't really work of it's a squirt gun's worth vs a bonfire.
The big takeaway from all of this however was that, regardless how strong someone's cultivation formula might be, they could still have a glaring weakness that someone could take advantage of.
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As Zhen Liu stayed on the ground, panting from exhaustion and lingering pain while Zhen Hai watched over him, Alicia, Jin Fang, Matilda and Harriet had finally caught up to them. Of the four, Jin Fang and Alicia were the first to rush to Zhen Liu's side to see if he was okay.
"Zhen Hai! Zhen Liu! What happened?," Alicia asked as soon she got to Zhen Liu's left side. As for Jin Fang, she immediately placed herself to Zhen Liu's right and helped to stand him up. He still looked sickly pale though.
"What's going with...the puppet?," Jin Fang asked.
"I...don't know. We had managed to corner that old fogey when he suddenly pulled out a shamisen and used a weird music art. It caused me to flinch for a moment, but it really did a number on Zhen Liu for some reason. Even the puppet started to mimic him."
"Please stop talking so loudly...my headache is starting to move to my stomach...," Zhen Liu groaned. He and Nepherage may have no longer be in active pain, they were still feeling the aftereffects of their sudden aches.
'Hey...voice? What's the deal with the feedback? I know it can't just be music, I have heard street musicians play back home and I never got sick .'
the voice in Zhen Liu's head replied,
'What's that supposed to mean?'
'Can affect a kaijin's core directly and subsequently, me,' Zhen Liu concluded, 'Gonna need to figure a counter to that...'
"Oh no, he's not looking too well...," Harriet muttered as she took in Zhen Liu's lethargic state, "Wait! I know! I have just the art for this type of thing!"
Harriet began to fiddle with one of the rings on her fingers, a subtle wave of rare spatial aether coming off of it.
'Of course she's a rich girl with a pocket ring, I have got to find me one of those...'.
"That's not it...ah!," Harriet muttered as she looked through her dimensional ring. From her perspective, she was probably looking at like a screen interface or the inside of a purse, but from an outside point of view, it just look like she was just fidgeting her ring back and forth. "
"There it is!," she suddenly exclaimed after a few more seconds of fiddling.
From the ring materialized what appeared to be a hand bell with an angel motif to it, the sight of which caused Zhen Liu to mildly grimace.
"Alright Monsieur Liu, be still and allow the healing tones to wash over you," Harriet cheerily said with a sweet smile. She began to circulate aether into the bell, causing it to hum with a strange, vaguely holy, sound.
"Wait...no... don't," Zhen Liu weakly protested as he attempted to reach out. Unfortunately, he was a bit too weak and just lamely dropped his hand.
A wave of soothing sound filled the area as Harriet rang the bell, causing it's listeners to feel a lot more relaxed as the sound wave washed over them. Well...most of it's listeners.
As soon as the sound waves reached Nepherage, her pupils suddenly dialated as her core started vibrating with more energy.
"Huh...that's a really nice-"
"YELP!," Zhen Liu suddenly squeaked as he freed himself from Alicia and Jin Fang and take a few strange steps forward. Behind him, Nepherage did the exact same movements.
"Zhen Liu? Are you okay?"
"Hey what's up with the puppet?"
'Oh this is gonna get weird...'
Wave after wave of energy came flowing through Nepherage's bond with Zhen Liu, filling him with power down to his nails. On a weirder note, he felt as if his nerves and bones were burning Ina pleasant manner.
The sheer amount of power flowing through him caused his body to energetically fidget shake in place. He was also mildly glowing, but the noon day sun made it hard for people to notice. It was still rather weird sight to everyone else involved.
"Harriet...are you sure you used the right support art?," Alicia asked with a wary eye.
"Mon Ami! Of course I did. I may not know some things about the world at large, but I am infallible when it comes to support arts!"
"Well whatever that art did, it's causing the puppet to freak out too," Zhen Hai pointed out as he pointed a literal finger at Nepherage, who was shaking in a manner similar to Zhen Liu's movement.
This strange motion went on for several seconds before Jin Fang attempted to get closer.
But before she could ask how he was, Zhen Liu and Nepherage suddenly stopped shaking in place and stood perfectly still. A weird look was on the former's face.
"Xi-Young Master? Are you okay?," Jin Fang asked with a concerned look.
"Step...back...gonna...vomit," Zhen Liu managed to eke out before having to hold his mouth. This gave time for everyone else to give a wide berth so that Zhen Liu could spew without worry.
However, none of them were ready for what was about to come out of his mouth.
"Gah! What the hells?! What's with all the smoke?"
"And why does it smell so bad?"
Instead of the usual liquid payload that comes with vomiting, Zhen Liu instead released a weird black gas from his throat.
'Huh...why does everything feel...nicer?'