Merlin's arms slowly faded into invisibility the further away they got from his shoulder; and what they turned into was something absolutely abhorrent and disgusting to the spirits that Eiro had just summoned. Gondos, having the best perception out of the three spirits, fused into the Demon's body.
While he was already able to sense and even see magic to a degree, while being fused with a spirit, it was still much stronger and a lot more natural. And more importantly, he could experience the nature of that magic for himself.
It was similar to arcane magic; but shifted and twisted into something that shouldn't be possible. Regular arcane magic was a sort of 'pure' form of magic. Instead of infusing mana with elemental magic or even internal concepts in some cases, pure mana was transmuted into something else.
It was basically turning mana into its own 'element', which if Eiro had to give it a name, was simply the 'Element of Magic' in itself. And this was similar; it was a direct transmutation of mana into something else. If Eiro were to give this version a name, it would be something along the lines of the 'Element of Aberration'.
In every sense of the word, it was 'wrong', and maybe that was exactly what 'the Fool' had gifted to Merlin. The ability to change the normal into the abnormal. The essence of wrongness.
The moment he realized this in his mind, his senses went absolutely wild. The domain of truth and order that was infused into his whole being was practically trying to reject what stood before Eiro, because it just should not be. It stepped out of the current 'order' of the world. It wasn't even a force of Chaos, which Eiro was also able to manipulate to a certain degree.
While order and chaos were two sides of the same coin, unable to exist without the other, this was basically the equivalent of a piece of dirt stuck to the inside of your wallet.
And then, Merlin raised his hand. Eiro could feel the air around the corrupted mage shift. He was controlling the air, but not through air magic. It was as though he simply bent the space around him, willing the air to do as he told.
However, no matter how aberrant Merlin's magic was, at the end of the day, he was still a highly-trained mage, and that was something that couldn't change all that easily. He still made use of techniques and knowledge that he had gathered during his life before becoming a monster in order to actually accomplish what he wanted to.
As such, once he overcame the initial shock of seeing the aberration magic, he began to understand the bits and pieces of order and chaos that had been instilled into that force by Merlin's mind. No matter how far one changed, there were still traces of the old left. Despite becoming a completely new and unique species, in the end, Eiro was still a 'Demon'.
And Merlin, no matter how crooked and distorted, still had the mind of a man. And it was impossible for any person to act in a completely unpredictable way. No matter how 'wrong' the aberration magic seemed, it was impossible for the arcane shards to give something of this world something of not this world; that in itself would completely overstep the boundaries of the cards.
Whether it was some kind of pride placed deep into his blood, or something that was simply caused by his own narcissistic tendencies, but even if his whole body was broken and ruined, he refused to let something like Merlin defile his horns and use the magic within them for himself.
Doing something vastly physically uncomfortable, Eiro began to manipulate the magic that was infused into his body through Gondos, tugging at the back of his own head.
'Sorry, I didn't mean to be so rough...' Eiro thought to Gondos, who, while experiencing some discomfort by what Eiro had done, was more focused on the battle right now. The demon's leg was still stuck in Merlin's barrier as it absorbed any sort of kinetic energy that Eiro was trying to use to move away, as though his leg was basically fixed in space permanently.
The only way that he could figure out to escape was to remove his fusion with Gondos, which quickly reduced the bulkiness of Eiro's leg to what it was originally, giving him the wiggle-room that he needed to pull back. Gondos was pushed out from the center of Eiro's back, and at that point, Sarius had already been rushing over toward him, quickly taking the Golem's place in Eiro's body.
If Gondos' specialty was his magical perception, then Sarius' was his raw yet unbridled power. And with Eiro's help, that power could be controlled and focused in ways that Sarius wouldn't be able to accomplish himself just yet.
Using the wave of fire magic that pulsated throughout his body now, Eiro let the flames push out from his leg, not only propulsing him away from Merlin again, but also enveloping the Fool in a mass of flames greater than he able to take control of and aberrate right away.
As the demon built up a short distance again, he could tell that the fire magic was doing its job, scorching Merlin's physical body. But it was to a lesser degree than Eiro hoped, as before long, a wave of aberration flowed through the flame magic. Both Eiro and Sarius could feel their connection to the magic wane; not disappear, but simply weaken.
But at the same time, not being fully disconnected yet, they could feel the creeping of the aberration. As though, using the fire magic as a conduit, it was going to infect them as well. Instantly, they cut off the connection themselves, giving Merlin free reign of the magic.
And as a distorted version of that fire magic gathered around Merlin's body, Eiro once more felt his mind be filled with confusion. That in itself shouldn't be possible. He had infused the aberrant magic with flames, or maybe the other way around. Even Eiro wasn't able to do something like that; Arcane Magic couldn't coexist with elemental magic within the same mass of energy, it couldn't be fused.
Or rather, it should be impossible to.
The demon ground his teeth, as he quickly began to try and truly understand the Mage of Aberration that stood before him.