Hmmm.....
There are a number of different substrates you can use for sealing. Most of them would cause Kagome to start screaming, etc., etc...
I wonder if
anything at all* would happen if you
carved a seal into the countryside.
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*Tangent, but it's related to what I think might be the most likely outcome:
In my very first session of D&D, in my very first "campaign"(that never went further than this session), one of my party members had a
brilliant idea
/s .
Player: "Hey, can I summon Cthulhu?"
DM: "....."
Player: "Like, make a magic circle and start chanting ''Cthulhu r'lyeh ia" or some stuff and get him to do my bidding?"
DM: "........................."
DM: "Let me tell you what is going to happen if you try to do that. First of all, like I've already said in the exposition, this town that you're passing through isn't very friendly to magic users because [plot reasons]. Assuming you just do that in a field, or Gods forbid, in the middle of town, the constable will just lock you up for Sorcerous Machinations. If you do this in your room at the Inn, the Innkeeper will beat the shit out of you, and then call the constable, and then you'll be locked up for Sorcerous Machinations."
(Somewhere in this the player tried to interrupt, but the DM fired back with something like "hey, we talked about doing stupid shit before we all got together. Don't.")
DM: "Now, say you went somewhere out of the way, where people wouldn't find you, and you go and carve a magic circle in the middle of the forest or something, something that looks like a nice summoning array to your untrained eye, and you stand in front of it and start chanting."
DM: "Even if you stood there and chanted nonstop through the day and night, forgoing sleep, food, and water, continuously taking penalties until you died, you still would not summon an Eldritch Horror. Even if it existed - which by the way, your character should have no reason to believe it does - you would literally have better luck asking Pelor* to kill a random commoner, 'just because'."
*Pelor is a Lawful Good deity in D&D.
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Anyway, DM-rant aside, "nothing happens" seems like the most likely outcome of (at least the early (i.e., first few hundred years of) forays into) Sealing shenanigans like that.