Corral Isle is a shallow island off the south coast of Sehto.
Its name is a pun on wildlife it doesn't really possess notable amounts of, combined with its brief history as an attempted penal colony. As such, there's a single abandoned building on it, now mostly in ruins, having served as a prison a few centuries ago.
These days, the interesting part of Corral Isle is its geographic design. Its structure is reminiscent of Roaring Hollow, subject to similar erosion forces, though its passages and caverns are all considerably more… horizontal in design, in parts giving the island an appearance of consisting of massive stone flakes.
Reputation and Genuine Hazards
Corral Isle is not quite as riddled with superstition in public perception as the Vereheq Ruins, but people have been reported to go missing here. As with Roaring Hollow, it's commonly assumed they simply went exploring on their own (which is true) and ended up falling prey to the treacherous landscape while trying to climb or dive (which is commonly not).
Specifically, not all underground passages carved into Corral Isle are filled with water - though those that aren't should not be frequented, as the reason they're drained is due to Crinyx's explicit tampering. As such, once can consider the whole island's network of dry subterranean tunnels part of a fortress of his own design - and he's certainly intensely territorial about it.
Every once in a while, he'll not bother with a clean kill, and instead play with his prey, quite content in setting the hapless human free somewhere in the depths of the labyrinthine structure with the promise of a chance to escape, only to hunt them down with relish. Fortunately, such a fate is rare, owing in part the lack of trespassing humans to torment, and in part that Crinyx rarely truly thirsts for an actual outlet for Council frustrations, both criteria which need to be satisfied for him to bother with such cruelty.
No uninvited human's ever escaped Crinyx's labyrinth alive; but it's quite unlikely he'd really let them go if they did. Being a good swimmer, a very keen tracker and a stubborn, vengeful spirit, losing him without some kind of help (e.g. from pokémon with Fly or Teleport) would be borderline impossible.
Pokémon, of course, are the first thing Crinyx takes off people - and he quite readily releases them back into the wild. Rather than doing so on the island, he regularly swims to the Sehto mainland at night time during days where visitors to the island are scarce or non-existent and will valiantly trek for miles to find a suitable habitat for the liberated pokémon. One shouldn't confuse this with empathy - while it's true that he does it with their best interest in mind, he can't understand the subtleties of non-Legendary pokémon emotion, himself, and so a pokémon lost and afraid in its new surroundings will just be met with a dismissive confusion.