Amity Park is her. Not hers; her.
She doesn't go by the name Jazz any more, most of the time. The appellation is too small. Her former body has aged, fallen to dust.
She remains, part of the giant city that was once small Amity Park. It keeps its name, but as grown, guided by her to something great. Vehicles float through the skies as, from far away, Amity's towers touch the sunlight.
She sees it all, watching the city grow, change. She watches the people thrive. Only rarely does she need to intervene.
Danny lived a long time. He's dead now; inhabiting the Ghost Zone with his parents. His descendants come to visit, at times; the city provides for them. Jazz reforms, machine into body, so that that his children and grandchildren may meet their aunt and great-aunt.
There are happy times, but they end too soon.
Lately, she has been contemplating. There's very little left to her. The city practically runs itself. Each generation of her descendants forgets her a little bit more.
It's close to her time. She can feel it in the rush of traffic around her, the cables under her streets. What could be her blood, what replaced her bones.
Soon, it'll be her time to let go.
Not, however, before she finds a successor.
She— Jazz, for a nebulous moment— lets her attention wander through the city until she finds who she's looking for. A girl. About the age of 16. She checks her personality, finds it studious, contemplative, planning; a good match.
Briefly, she notices in the genealogical records that the girl is a descendent of Ms. Valerie Gray; then that fact is released as unimportant.
Planning for the transfer takes a day and a night. Slowly, carefully, Jazz unhooks from her developed city-body. Some systems are transferred over to automated control. Others are let run free; projections adjudge that future city development will be for the best this way.
Finally, there's only Jazz, her mind, and a swarm of glittering nanobots, like sunlight in air.
She pushes herself out into the sky, admiring the gradiated beauty of the dawn skies as 'she' flies above Amity's far suburbs. Estimating a location, she hovers, swarms, lets the fair winds blow her towards her destination.
There she is. 16 years old. Dark hair. Backpack. Determined expression. Readying herself for school.
The girl finishes, takes a step outside the house, unaware of the impeding change to her destiny.
The mind that used to be Jazz Fenton, metaphorically, closes her eyes.
Nanobots crash into the girl, moving through her skin and into blood and bone. She almost doesn't notice; there's no initial sign of their presence.
Soon, though, the powers will come slowly. Just as they once did for Jazz.
As the bots move into their set tasks, Jazz Fenton's mind slowly dissolves. The mantle is no longer hers, now. It's time to rest.
One last splash of the girl's mind appears before her; she metaphorically smiles, a split second before she's gone.
She knows what the future will bring.
Amity Park will be safe and well; forever and forever.