A dragon falls in love with a girl, give up his immortality so they can have kid.
Later on the dad die because of his mortality (the mom most likely long gone before), is reborn as his daughter’s pet dragon.
And one day human decide to hunt the pet dragon and kill it.
The girl proceed to slaughter the foolish human in her sorrow, awakening as demon lord.
As part of her awakening, the dragon is resurrected as chaos dragon, causing more damage.
The ‘friends’ of the girl finally was able to break her out of her rampage, and the girl herself puts down her pet.
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Is this me in a nutshell?
Pretty much.
