The most senior definition of that which makes “you” distinguishable from other “selves”.
The real-you (of just under half the humans on earth at this time), i.e. that-which-places-spirit (spirit being just another form of body).
Ultimate Self includes existence senior to this chain of universes, as well as within it (existence in any one universe requires existence in all universes above that in the chain, although one doesn’t necessarily have to be involved in the Playing-field of each).
It’s fundamental properties are awareness and the ability to create . . . these two things appearing separate (as two poles of one thing) within the universe-chain-container, and not separate outside that. Ultimate Self can create, directly (there are no fundamental limits to this ability, no matter how many considered limits are added, although it is rarely used).
While there are relevant locations, including a location outside the universe-chain which connects to ones presence inside the chain, and a location just outside each Playing-field from which one projects ones presence in the Playing-field, the essence of Ultimate Self -i is located outside, and senior to, any of this.
A new Ultimate Self can be created on a human body that doesn’t have one. See the relevant page on energy-bodies.org for details on how various spiritual traditions do that.
A new Ultimate Self is typically in a very different condition from that of a “fallen god”. A new Ultimate Self is usually created in a less than ideal condition, as that’s what this universe specifies (although that condition can be bypassed by some advanced methods).
At the time of Yeshua, very few humans on earth had a Ultimate Self, but just before the time of the Renaissance, two planets in nearby solar systems were rendered incapable of sustaining advanced life-forms, and the located parts of the Ultimate Self’s from those planets were brought to earth and took human bodies here (mostly in Europe, due to preferences for societies there), hence the Renaissance (a human with a Ultimate Self has significantly different interests from one without).
Ultimate Self’s have also arrived on earth before and after that time, and some have left to go elsewhere (and a few have got themselves free of this universe entirely, and currently function in the infinite-life universe or above there). One example is relatively small numbers arriving in Naka bodies (similar to a Chinese water-dragon) mainly in Asia.
Ultimate Self considers itself to Have (and/or own) various things in various universes (and outside universes in the Substrate). These include structures of non-ideals (automatic limitations).
The main mechanism of starting to add non-ideals in a universe-chain is decaying while playing games. A Game is defined as an area where one Agrees to certain limitations (the rules), but typically one will start to believe those limitations are “real”, thus considering oneself limited.