Not sure what to call this..

[Crash Ichimonji]

While it's a male version, who could forget Obi-Won's 'death' in Star Wars Episode IV? Death in body, but it allowed him to become an immortal spirit form.

I recall back on the Nickelodeon series "Allen Strange" a male version of said process happened as well. Basically, a mold on some bread got radically evolved into a perfect copy of some guy at the kids' school, and at the very end he got evolved even more until he phased out into thin air. It was explained, however, that he became a higher form of existence by becoming one with everything on Earth.

*SPOILER ALERT BELOW*

While it's not exactly the same, the end of humanity in 'End of Evangelion' seems similar. Rather than disappearing, everyone's AT Fields were compromised and reduced their bodies to basic LCL while their souls gathered to a unified existence (until Shinji trolled them at the end).