Ipsissimus

"An Ipsissimus is free from limitations and necessity and lives in perfect balance with the manifest universe. Essentially, the highest mode of attainment. This grade corresponds to Kether on the Tree of Life. Ipsissimus is quite hard to translate directly from Latin to English, but it is essentially the superlative of "self,” translating rather approximately to "His most Selfness," or "self-est." (c.f. generalissimus for the same superlative form in use for a grade from same Latin root.)" 1

Source: 1. https://en.wikipedia.org/wiki/A%E2%88%B4A%E2%88%B4#:~:text=Ipsissimus%20is%20quite%20hard%20to,grade%20from%20same%20Latin%20root.)