Merri, despite stumbling upon the knowledge that there was indeed something wrong with Arc, did not immediately make a fuss. This was not entirely out of the realm of expectation. Marlev's death was an extremely traumatic event in regards to Arc's body, so some abnormality within his body absorbing Xan in order to heal itself could exist.
A child surviving a Mother's Nexus break upon birth was effectively one in a thousand, with the survival rate decreasing as the mother's power increased.
This level of rarity would make it feasible for some otherwise unheard of condition to exist.
What bothered Merri the most about it was that she could not determine the location, nature, or severity of the problem. As a result, she had no idea how to 'cure' it and had to resort the time honored method of throwing shit at a wall. The theory behind which was "If you throw enough shit at a wall, eventually some of it will stick."
In practice, this meant that eventually after absorbing enough Xan, whatever the anomaly would either be satiated and stop or elicit some sort of change or reaction.
If it was saturated and nothing happened? No big deal, it was probably some sort of extreme deficiency or damage that would have been remedied on its own somewhere down the line.
If it elicited a positive change? All the better. Having a benefit from the get go in life was not something to look down on.
If it elicited a negative change? Needless to say it would be better to be found now rather than later. Should it be something that would be harmful down the line she could immediately get to work finding a remedy. Should it be something more immediately dangerous, the two most powerful cultivators in 100 miles and one of the foremost experts on alchemy lived in this mansion.
If the issue could not be solved with these three within a moment's notice, there would really only be a single person in the world who could save him, and she only showed her face every couple of years to complete strangers.
It really was a case of 'if he dies, he dies.'
If there was nothing they could do, there was nothing they should do.
Luckily for, and unbeknownst to, Merri, there was zero chance of such an anomaly. More accurately, Arc WAS the anomaly. Merri's normally correct perception of what someone his age should be able to bear simply did not apply.
It would take a concentration of Xan several orders of magnitude higher than what she was currently forcing upon him in order to evoke the same side effects she was looking for. He would actually reach the point of his skin tearing from the Xan entering his body too quickly before that occurred at his current age, so reaching that level was out of the question.
However Merri, clueless to the truth of the matter, would continue with her slathering of the gel on Arc's chest for some time.
-----
'What is she doing?'
Arc was befuddled by Merri's actions. His extremely limited general knowledge of the world meant that he didn't know what she was putting on his skin, and his notably lacking knowledge of Xan and its workings with the human body meant that he had no idea what she was trying to achieve.
He gathered that this gel had something to do with 'healing' as he heard the conversations of the adults around him. The flow of Xan into his body from this gel did not go unnoticed either, but that didn't really bother him. He was grateful for the increase of Xan at his disposal, but as far as he could tell no one was aware of his ability to cultivate.
So the question of 'what' she was doing was answered - slathering his chest with that strange gel - but it was really more of a 'why'.
Racking his brain for the little information he did know he came up with a few possibilities.
- She was trying to help him cultivate.
The problem with that was he knew through Bell's (rather painful) instruction that people in general cultivated by drawing Xan into their lungs before sending it to their Nexus. He could safely rule that possibility out,
- She was trying to 'heal' something in his chest area.
That would be believable if he had ever been injured there, but up to this point his chest felt fine. Perhaps, and this was a really small chance, there was something wrong with him and he was simply unaware of it. This was possibility was reasonable, but unlikely.
- She was testing something.
Not entirely unreasonable, but equal parts unlikely. He had come to the (accurate) conclusion that Merri viewed him as something of a nephew and would do pretty much anything in her power to protect him. Taking into account this gel was something she trusted enough to use on a baby, there was probably not much that she could discover by testing on him.
- She was taking preventative measures.
Perhaps there was something about this gel that would prevent something harmful in the future. This was by far the most likely possibility given his current knowledge. The only issue with this was that he had no idea what it was to prevent against.
Anything physical was out of the question. Try as he might to deny it, he was still just an infant. If there was something that threatened to injure his body, there was little that this gel was going to be able to do to stop it, especially if it only covered his sternum. It could ostensibly heal a wound that might occur in that region, but that would require the foresight that he was going to be injured there in the first place.
If you know I'm gonna be injured there, surely a better course of action would be to do away with the cause entirely right? Even if he would be the one to injure himself Arc couldn't exactly put up resistance at this point in his life.
He could see this as a prevention against infection, though he wondered why on the middle of his chest. He had never exactly been in a state that he would consider filthy. Certainly he had been unhygienic at times as that is the nature of a baby, and he could certainly see where places his caretakers could not wash well might be a risk for infection.
However his chest was not one of those places. Not only was his chest rarely even sweaty, but it was not nearly as hard to clean as his toes and ears. The existence of something beneath his skin was out of the question too. He had never been cut or scraped, and his skin was as smooth as a baby's bottom in the most literal way.
And so he lay there, baffled, with increasing concern.
She must have a good reason for doing this, he just couldn't see it.