15 loops and still going. I don't know what can stop me at this point. Most enemies have 999 stats or close to it. There are some enemies that kill some of my monsters, but never all of them and not nearly enough. I can easily take off wounds beating bosses and using salves and the elixir on Wyrmlet.
More time passes, the more I find Iron Wills to give to monsters. Iron Will kills my original swap strat a bit (Tizik is basically a wall with some useful synergy right now), but it's almost impenetrable. Maybe only Skimander/Chip are worth leaving this way, without Iron Will, to use Swap strategy with them and switching Chip with hurt allies to heal them (thanks to Seras power that heals when you swap).
I'll continue a bit, maybe till enemies always have 999 in every stat (except Spd, because that looks like does not increase), but after a while I think I'll call it over and declare that this team is, indeed, unstoppable. It can be hurt by the game as it is now, but I'm not sure it can be beaten.
I could be wrong though. Don't know if incredibly high loops have some stuff I'm not taking in consideration.