If it is just a typical isekai style, we all know that Teyvat, specifically the Irminsul, is quite aware of who is a native of Teyvat and who is a descender. Which means that the world of Teyvat would be aware that MC is a descender, but a unique type of descender. I like to think that since MC just randomly spawn in Genshin, Irminsul just in a constant erasure/rewrite about the MC.

Like it is contemplating that yes, MC is a descender, but at the same time, MC is somewhat human within Teyvat. This could also unknowingly help the MC from being suspected by other people as normal people could simply sense them as ‘part’. While the ones with so much self awareness of what is local and what is foreign. Obviously MC doesn’t know that, but hey, they don’t need to.

In terms of survival, I do see a very lore self-aware MC, meaning they are most likely to avoid every important character that has much relevance in the game. Even if those characters are just special characters from events, they would still avoid those characters as they are connected to the Traveller.

Speaking of the Traveller. I can assume that the Traveller can sense that something is amiss whenever they would have a brief passing with MC. It is like they can sense there is something out of place but they can’t place their finger on what it is. I like to think it relates to both of them being unknown to the world, but again, Irminsul is just helping MC more than the Traveller.

Meanwhile, MC has been playing NPC within Liyue and Mondstadt. Avoiding going to Inazuma with its strict military and decree (and even if it was lifted, MC wouldn’t take the risk). Sumeru would be a 50/50 journey to go as it literally houses the most Leyline connection throughout Teyvat. In MC’s opinion, as long as they avoid going to the central Sumeru and important villages, no one can suspect them. Natlan would be easy to journey around as they are quite isolated from other nations, though it still needs verification about someone’s identity. MC can just… avoid it. Fontaine and Nod-Krai? No. A nation that literally the Laws itself? Ha, good luck. A dominion nation that is filled with Fatuus and the possibility of being snitched to the Cryo Archon that there is another descender? Fat no.

Although Liyue could also be a 50/50, as long MC is just being a harmless bystander I don’t think the Yaksha or even the millelith wouldn’t do anything to them.

NOW. The part where MC gets discovered. I am more leaning realistically for this part, but I like to think how they got discovered would be when Nahida first met with Rukkhadevata in Irminsul. After the event in Sumeru and during the part where the Traveller was asking Nahida about the whereabouts of their twin. Nahida would also murmur how the Irminsul often ‘wavers’ around if she goes deeper. She of course does not understand why it does this, but brushes off as of now.

Now the time where they actually would put this accident a concern would be during the Wanderer story quest. Where the Traveller and Wanderer go to Irminsul to re-experience his erased memories. During that time, they would feel the Irminsul would start ‘glitching’ then fixing itself. This would repeat a few times then go back to normal.

They would obviously inform Nahida, then they go to a deep-dive and soon realize that the Irminsul is trying to protect a wandering descender that was never discovered for the longest time. Where everyone would often be so suspicious of the Traveller for being too foreign, the MC, again, would just get a pass. All because of Irminsul.