After so many years, I've finally beaten Zero Isle South on Pokémon Mystery Dungeon: Explorers of Darkness.
I first played through this game when I was a young teen and did almost every dungeon available in that game, the only ones that stopped me were the Zero Isles.
When I replayed it several years later, a similar phenomenon happened, except I might've beaten one of the easier Zero Isles.
Now, I beat Zero Isle West and East about a month ago after a replay, and will do North later once I've gotten enough joy/golden seeds and gummis for it, but South was always the notoriously brutal one. I theorycrafted for it myself and didn't use a guide (outside of checking the floors to use keys on for treasure). One of my first strategies was to use a Miltank, which worked really well and eventually got me all the way up to floor 97 after a few tries, but a bad spawn fucked me right before finishing and left me fucking PISSED. Its a great pokemon. Scrappy ensures you can fight ghost types, thick fat protects against fire and ice, and 3-4 defense curls on each floor protects you from a lot of damage, until you get screeched. Plus it's moveset is just solid and it's stats are great.
Then I briefly tried Groudon and some other random pokemon. Groudon got to the mid-80s on his first try but the next few tries failed.
Finally I decided to try Garchomp on a whim, and this thing is fucking busted in there. Granted I got a bit lucky with TMs, getting Dragon Claw and 4+ Ginsengs to boost it along with an assload of joy seeds and sitrus/life seeds, but still damn, what a ride. Sand Veil and 14 PP sandstorm is just broken. Permanent weather control, most enemies weaken or die over time, you get it from level one, and his early moveset is great with Dragon Rage, tackle, fire fang, and sandstorm. Not to mention his stats are obscene for his early level, but his early leveling is a bit slow.
Zero Isle South is just so fucking brutal. I can't imagine what Explorers of Sky's last Dungeons are going to be like when I get around to it, as I heard they added a dungeon that's supposed to be even harder than it somehow.
PMD Explorers is just so damn fun. Thus far its the only PMD game I've felt like (and enjoyed) doing the post-game for ever since I was a teen, probably because everything about it is so damn good.