Jon didn't kill Daenerys, simply left King's Landing and decided to live out his days alone with the Wildlings, cutting off all communication with the rest of the Seven Kingdoms. Fourteen years later boy with black hair and purple eyes appears in Jon's village, claiming to be his son.

Daenerys is resurrected, and gives birth to twins. A year after their birth, her daughter goes missing. She never stops searching, and years later she brings fire and blood back to Westeros when she receives word that the Princess of Dragonstone is a girl with silver hair.

Before Jon Snow ventures south to meet with the Dragon Queen Brandon Stark returns to Winterfell and Samwell Tarly sends a letter. Jon uses the knowledge of his birthright as leverage, shifting the entire course of his and his aunt's negotiations and resulting in an interesting proposal.

Jon changes his mind a few seconds after rejecting Daenerys, deciding to embrace his true Targaryen nature. The Mad King and Queen shall reign down fire and blood upon all those that sought to tear them asunder.