He knew his death would only be temporary, but the fact that this mortal would over power him was an affront to the gods, him in particular. With his last breath, the minor phoenix gog Saffron uttered a death curse upon the one who would strike him down. And Ranma did strike the final blow to save the life of Akane. The phoenix's curse, a construct of divine magic did not account for the multitude of curses and blessings already present upon the boy.
Nodoka, had when he was a baby, wanted the best for her son, so she had sought out the most powerful blessings she could find, starting with a temple devoted to a goddess of luck where her child received a powerful blessing. Every shrine and temple she visited thereafter, he had been lucky enough to garner the attention of the gods, though they had not necessarily cared about making their blessings compatible.
His father had taken him to many sacred places to train and he had been put through many forbidden training methods. His father's methods had garnered him more than a few blessings and curses, not the least of which were the neko-ken ritual which summons a protective feline spirit and implants it in the spirit of a child and the body changing curse acquired from Jusenkyo which had actually been created by the deity who had become known as Janus before he moved on to Greece.
Then of course there were the various plans od those around Nerima. Many involved objects of dubious origin, including ones full of incredibly powerful magics. It was inevitible that he would end up with many more blessings and curses, not the least of which was from that cat spirit that wanted a bride.
All in all his body was practically ready to explode with conflicting divine energy. It was into this kettle of madness that the death curse struck. It was unfortunate for Safron that he desinged the curse to kill one person and the body essentially held three. The barriers between the cat, girl and boy collapsed as all three were temporarily weakened and divine energy flooded the body of the new being. The body, having this divine energy from its creation, considered this a normal state of affairs and generated more of the divine energy. With divine energy in his system, curses were recognized as negative and were worn away while blessings were absorbed and integrated and strengthened.
As Ranma rescued Akane from the crumbling mountain, he was surprised to see that though wet, he had remained a man. Surprisingly, when he admitted feelings for Akane, she responded in kind. Her previous constant undeserved anger towards him had disappeared.
When preparing for the wedding, he ran into Cologne who wanted to follow up on what had happened with Saffron. She explained to the family what had happened to him and that since he was now a god there was now no need to choose which fiancee to marry as he was even above a king now, it was expected of him to have multiple wives and concubines, so it would be dishonorable to dismiss any of his legitimate fiancees. That resulted in the proceedings becoming much larger as he had many fiancees and his mother made sure that Genma revealed them all. In the end Ranma Kami of martial arts was married to nearly every martial arts family except the Kunos (despite Kodachi's protests) who had a daughter his age due to Genma's trickery. It was a very large ceremony and Ranma swore that he would master the techniques of every one of their families and any others he could find or create.
Fifty years later, a new legend was spread of a newly created village where the god of martial arts lived with his descendants, even a child of that family capable of fighting entire armies.