>>30901360The Battle Tree isn't hard, it's just a battle of attrition.
The AI is dogshit (will not switch unless it is incapable of dealing damage to your pokemon: even if it has -6 attack and only has quad resisted moves, it won't switch. Can be PP stalled effortlessly through immunities, e.g. the infamous sash hypnosis dream eater Gengar can be PP stalled by continuously switching between a sleeping and a non-sleeping pokemon)
The sets are 80% gimmick garbage that makes showderp memes look good (e.g. Choice Band Latias)
The only way you actually lose is by either bringing in your in-game team with random IV's/EV's, or through getting unlucky: which, through the high volume of battles, is going to happen eventually.