I've beaten it a couple different ways at this point.
Make sure to defeat all enemies at least once for their moves, max out items for the stats, and complete events for move-granting items, since those persist between runs.
Without spoiling specific strategies, once you've done that, the game loop is essentially figuring out a winning combination of moves, cascade upgrades (particularly 10ish point Ascension capstones), and mutations to defeat the last few enemies.
I can confirm that at your level and with a purely human set of mutations, that enemy is beatable with a combination of just three moves (and some luck), all of which are human/technological.