What should be the Deception DC to detect a Shinigami's true form?

[Rukiri]

Shinigami have the "change shape" ability, which says the shape counts as a disguise use of Impersonate. Though they auto defeat checks to see if they're actually a creature of that type, and get +4 to prevent others from seeing through their disguise.

Impersonate says the players does a perception check against the creature's deception DC.

Shinigami don't have deception as a trained skill.

So, my understanding is RAW, the deception DC would be Charisma + 10 + 4. Which would be 23.

For a level 17 creature, isn't this way too low? Should level be added? Or is a Shinigami's "human form" a baseball cap and sunglasses?

[Perpdepog]

Probably best to give it its level to Deception, or bump it a teeny bit so it's the same as its Diplomacy at 32. That'd give it a DC of 42, or 46 to see through its disguises, which feels a lot closer to a level 17 creature.

[SuperParkourio]

What if being untrained is intentional? After being constantly screwed over by PFS skill challenges that only allow the handful of skills I'm not trained in, it'd be nice to see at least one high level monster be screwed over the same way. Perhaps the shinigami just avoids direct interactions to rely on the auto success, but things go wrong for the shinigami the instant they arouse suspicion.

[Castilliano]

Or one could allow for letting it add its level even untrained, much like some other disguise abilities allow. Assuming it's meant to succeed in mundane conditions.

[vegetalss4]

Given the clause about automatically defeating perception to see if they are the ancestry they appear as, and that the Shinigami's change shape is limited to one singular unique humanoid shape and can't be used to impersonate a creature, I don't think the DC matter.

Looks to me like the Shinigami can only use it for the narrow cases where the ability is unbeatable