Well then you could split whatever world the punks are supposed to be in in two. Something like the younger and wilder mothers of the original breed allowed themselves to be drawn in by the punk lifestyle of the humans, leaving to live amongst them. The older male fathers of the original breed, fiercely protective of their daughters and the old ways, kept them on the old land away from the others.

The dragons could be other wildlife living in that world that live amongst the cats. The angelic lines could be gained from RP with the females, learning the old cultural music and becoming attuned to it and the traditional ways and growing into the angelic forms.
The demonic forms would be gained from RP with the males as the dragons indulged in the wild, fast-paced city punk lifestyle and are tainted by the music they fully adopt the lifestyle and grow into the demonic forms.

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Demonic Kowlas: Sometimes a tainted dragon from the city will leave its home in search of weaker elders who are susceptible to their corruption. The result is a Demonic dragon bonded to a Kowla that takes on a slightly more punkish tone to its original appearance.

Angelic Punks: There are those purified dragons that are so good that they believe themselves missionaries, venturing into the city to show the wild youth the light of the old ways. The outcome of one who can listen is an enlightened Kattie who's appearance has become more regal and ceremonial.

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