>>54799640I think Sun and Moon's Totem Pokemon was a good attempt at making a "wild Pokemon boss battle", but it was still too constrained by the standard 1v1 battle system (or 1v2 when it calls for help). They expand on it a little with the Titan Pokemon in Scarlet and Violet, but now you're stuck with a shitty tag partner.
I'd like to see a more RPG-like boss battle where you can throw out 4 of your own Pokemon vs 1 boss-level Pokemon with multiple health bars and can use multiple moves a turn. Like a single-player version of a Tera Raid.