I just defeated groudon as well, difficult as hell unless you have 5-6 revive seeds, i had to go back to the start of the dungeon to be able to access storage and take all my revive seeds, that and a protect mt i got while i was cimbling back i was able to defeat it, good rng is needed as precipice blades is broken, also depends your starters and attacks but yeah, from now on ill have to bring with me at least 5 revives