Everything is reset after each battle, so for each one your team has full HP and PP, any lost held items are returned, and so on.That means no Revives or Full Restores, but berries and held items like Leftovers are fine (and important!).
Pokémon above level 50 will be set to level 50 and their stats adjusted to what they would be at that level (taking into account EVs and IVs, too, so they're as important as ever). Pokémon up to level 50 will stay at their current level.There are several basic rules worth being aware of in the Battle Tree:
Battle Tree Rules, Battle Formats, Super Battles, and Banned Pokémon Here in this Battle Tree guide then, we'll be outlining everything you need to know for taking it on, including a list of Battle Tree rewards, Battle Formats, Special Trainers, Battle Legends Red and Blue and their Pokémon, and our best strategies for earning those all-important Battle Points. There are two main reasons for taking part in the Battle Tree: practicing your competitive battle skills offline, and earning Battle Points for rewards - which range from crucial competitive battle items like Choice Specs to Mega Stones for your rarest Pokémon - and none of those will be earned easily. Pitting you against competitive-quality Pokémon from across the generations, this is Gen 7's version of the Battle Tower, where you'll fight wave after wave of trainers, your Pokémon healed between each, until you lose a match. Pokémon Sun and Moon's Battle Tree is tough.