There are fourteen rakshasa immortals, and they're each CR 21-25. 

...Where CR 23 is supposed to represent a being somewhere in the ballpark of, chisanbop, a thousand and twenty-four times "more difficult to defeat" than a shadow?

It's kind of a goofy system.

What does CR 21-25 actually mean in this context?

It means 'meh, I can take them.'

Press X to doubt.

So, Cressida, to give an idea of the general range that 21-25 covers, a pit fiend is CR 20, a solar is CR 23, the weaker demigods like Ragathiel or Barbatos are CR 26.

Why the FUCK did you say that name?

Eh?

Oh, Barbatos is like Pazuzu in that 

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

....Oops.

Apparently solars are three times as difficult to defeat as pit fiends and Ragathiels are three times as difficult to defeat as solars?

That's... interesting to learn...

This all sounds incredibly made up. Who could possibly know a thing like that?

(Someone who owns all six of the Bestiaries, and the pocket edition releases of Bestiaries 1, 2, 3, and 4.)

(Someone who wikiwalks d20pfsrd and reads aon for fun.)

(Someone who has the stats for simulacrum versions of a pit fiends, solars, and Ragathiel all saved on her phone.)

(Someone who counts as friends all three of these people.)

No offense, Altronus, but if it comes to a fight between us and them my money's on the fourteen demigods with arcane ninths.

Barry, please.

If I can't faceroll dukes and maharajas by the time I'm level 12, just take me behind the barn and shoot me. 

It'd be a mercy.

(Why can't I SQUISH THEM while they are SMALL?)

Glorio Arkona is dancing on spun wire here. But if he plays his cards right. If he plays his cards right.

He's not the only live player who's gotten the inkling that these four are something weird. Probably all of Korvosa's live players know that by now, with the possible exception of Toff Ornelos (who keeps conspiring to be absent while people are talking). 

He is the only live player who has detect thoughts running on three of the four. Or at least, he is to his knowledge.

Glorio is being very forthcoming and she isn't sure why.

It's unnerving.

There are many Arkonas in Korvosa who, disturbed by Lord Arkona's conspicuous charity, would be worried that's he utterly cracked and is just being helpful.

But Melyia isn't among them. She's known "Glorio" since well before they chose to wear these faces. 

So what's his reason?

As nothing can kill them, as a rakshasa's powers grow with each life in direct proportion to how nastily they treated the other people in them, and as converts to the dhruva jivita - traitors to mortalkind, the blackest hearted of blackguards - do betimes convert others in turn, the wicked philosophy of dhruva jivita spreads inexorably.

He's trying to get ahead of the story. He doesn't think that he can deny the broad strokes after the spell revealed his cousin's face.

Melyia thinks, and thinks that Glorio thinks, that the samsaran is well-enough trusted by the Field Marshall and knows enough about rakshasa that House Arkona won't get anywhere lying about whether she is one or what rakshasa are. And... the samsaran probably knows enough about rakshasa to make the connection that every member of House Arkona present in this room is one. Where there's not only smoke but fire, there's likely more fire. And even if not, the samsaran knows enough for someone else to make that connection.