What happens to a devil who draws the balance card from a deck of many things? [duplicate]

Question

I recently read the accepted answer to this question, and this part brings a good question:

A devil does not choose to be lawful evil, and it doesn't tend toward lawful evil, but rather it is lawful evil in its essence. If it somehow ceased to be lawful evil, it would cease to be a devil.

The effect of a Balance card from the Deck of Many things reads:

Balance: Your mind suffers a wrenching alteration, causing your Alignment to change. Lawful becomes chaotic, good becomes evil, and vice versa. If you are true neutral or unaligned, this card has no effect on you.

So if a devil draws the card and becomes chaotic good, and such a change means it ceases to be a devil, then what is it instead? How does it change?

Answer 1

It would not be a devil

A chaotic good devil is a nullity - a thing that cannot exist. Since the creature is chaotic good it is ipso facto not a devil.

It looks like a devil and has all the same statistics and characteristics of a devil but it isn’t one. For mechanical purposes it would be exactly the same as the devil it was but philosophically it would be very different.

It is now free of the infernal hierarchy and can, indeed must, make its own ethical decisions in the future. Even if it chose to reject its new ethos and, over time, became lawful evil again, it still wouldn’t be a devil.

There is precedent for this:

Curse of Strahd includes a fallen Deva called The Abbot who has been corrupted by the Dark Powers of Barovia. He still uses the deva stat block but is not a deva.

Answer 2

It's up to the DM

There are examples in prior editions of devils and demons which have changed alignment from Lawful Evil (and other "primordial entities" which have done so - Chaotic Neutral modrons for example). See, for example, Fall-From-Grace, the Lawful Neutral succubus from Planescape: Torment.

Ultimately, there are no rules that I'm aware of that would determine the outcome here, and as such the DM would adjudicate what happens.

Answer 3

It'd most likely be classified as a celestial

Outsiders like devils, demons, and angels seem to work on a weird sliding scale of alignment. If you go from one alignment to the other, you essentially abandon your old classification and take up a new one. Even your statistics might change because your very fabric of existence has changed.

For example:

Zariel

Zariel was once a lawful good angel. She fell from grace because she wanted to intervene in the Blood War to aid the devils, and her alignment became lawful evil. She became a devil, and later an arch-devil.

She can also be redeemed in a new campaign book, in which case she becomes an angel again.

Azael

Azael was once a fallen lawful good angel, but he was punished for his evil deeds and sent to the Abyss, where his alignment became chaotic evil. He's now classified as a demon.

Graz'zt

Graz'zt (thanks for reminding me of his name, @NathanS) was a devil lord who betrayed Asmodeus because he tired of all the rules and went rogue, changing his alignment from lawful evil to chaotic evil. He's now classified as a demon and he's one of the demon lords of the Abyss.

So to answer your question, your devil in question would now be a Chaotic Good outsider. The hard divide between lawful good, chaotic good and neutral good in terms of Celestials is not quite as defined as it is for demons and devils, and I don't believe there's a generic overarching name for chaotic good celestials (unlike lawful good, which tend to be called angels), so 'celestial' would likely be the most likely new classification after drawing the card.