Pokemon Pearl: Spent a good deal of time at the Battle Tower while on a plane trip a few weeks back - yeah, got lazy on posting here, haven't had reliable internet access for one. After a couple of losses due to back luck (Hydro Pump hitting at -4 acc, Stone Edge missing), I opted to pull out the big guns: a pair of L100, EV trained Garchomp and Tyranitar I got from cloners. Also perfect IVs on both which guarantees they're hacked (they're shiny to boot), but eh, I got them for BT user only. Throw in my Bronzong for a third party member, for an all-sandstorm immune team.
Garchomp... is hideously overpowered for the Battle Tower. With a Choice Band it OHKOs damn near everything with Earthquake/Outrage except Skarmories and Bronzongs, and I can usually stall those down those with Bronzong (though a Spikes/Roar Skarm nearly killed me once). Even Palmer's Milotic falls to one hit from Outrage (hell, I've seen it get OHKO'd by Earthquake once). Tore through the first Palmer fight, made it the second one for the first time ever, and beat that on the first try as well. Garchomp 2HKO'd Regigigas and took an Ice Punch, then Cresselia came out and T-tar set up on it for free (Psychic/Shadow Ball for your offensive moves does that) to finish the match. Finally lost on the 63rd match when a Hitmonchan countered Garchomp to death (think it had Focus Sash... wasn't fully paying attention), then Medicham swept the remainder of my team.
Pokemon Emerald: Bought it, beat it, began operation Unlimited Cloning Works. Not much to say about the main game, I was hoarding all the OPG TMs like Earthquake so I opted to just run 3 Pokemon (Swampert, Swellow, Gardevoir) and rely on inflated levels and Garde buffing abuse to get through that. Some time later, I trained up two aftergame Pokemon and started work on the Battle Frontier. Mainly used the following 3 Pokemon:
Metagross @ Lum Berry (tried Choice Band out a bit, but prefer Lum)
Adamant nature
Meteor Mash
Earthquake
Aerial Ace
Shadow Ball
EVs: 252 HP, 252 Attack, 6 Speed
IVs: 24 / 18 / 5 / 19 / 31 / 5 (HP DRAGON YES)
Got an Adamant Beldum with passable IVs on the first try, so I opted to use it. The last two moves are a bit fillerish, but Aerial Ace has saved me from a couple of random Double Team abusers and I'm still debating Shadow Ball vs Rock Slide for the last slot.
Latias @ Leftovers
Bold nature
Dragon Claw
Calm Mind
Recover
Refresh/Safeguard (couldn't decide and ended up having one Latias with each via cloning)
EVs: 84 HP, 174 Special Attack, 252 Speed
Ivs: 6 / 21 / 5 / 9 / 9 / 2
Bold's a usable nature, but ;_; to those IVs. Incidentally, Latias absolutely refused to show up when I specifically tried to hunt for it (and I spent several hours doing that), then turned up randomly while I was EV training Metagross. Go figure.
Swampert @ Chesto Berry
Hardy nature
Earthquake
Surf
Ice Beam
Rest
Dunno the EVs/IVs since this is my starter from in-game. It works well enough for beating up steels who resist Latias and grounds who might give Metagross problems.
This team has problems with bulky waters - I pretty much need Latias to CM up without getting haxed there - and Heracross, who swept my whole team once. Works well enough for something that took relatively low amounts of work, at least.
Battle Factory: Blech, don't like the randomness of the Pokemon draw here. Got a good Tauros (Adamant, Facade/Earthquake/Thrash/Swagger@Persim Berry) right away first run and mainly rode it to victory, then a good Heracross (Jolly, Megahorn/Earthquake/Bulk Up/Attract@Lum Berry) and Kingdra (Modest, Surf/Ice Beam/Dragonbreath/Rest@Chesto Berry) second run. Third run I got utter crap for my starting selection and died on the first match. Not touching this again.
Battle Pyramid: Neat place, since it's mainly an endurance test with plenty of strategic potential. Lots of luck of course, but it's mostly of a managable sort. Made some dumb mistakes the first time through that cost me Swampert and Metagross on the early floors, then Latias got haxed by a Linoone near the end. Played more carefully on the subsequent run and made it through, then went back later and finished two more runs, beating Brandon on the first try since his team sucks. Getting a Choice Band as a random item on the second run through was *really* nice.
Latias was key here for Refresh to heal away the status that randoms spam and Recover to heal any damage taken. I used it as a lead except for the poison run where Metagross mostly led. After the first failed attempt I opted to almost always run from randoms to conserve PP; incidentally running attempts are total BS here, Latias should not be struggling to get away from lower level Weezings ever. Guess they did to up the challenge. Trainers on the other hand I generally fought if I saw one, since they frequently gave me directions on the exit. As for the Pyramid King, all Regi team had way too many shared weaknesses. Swampert 2HKO'd the leadoff Regirock with Surf and easily Earthquaked Registeel down as well. Switched Metagross into Regice's Ice Beam and promptedly OHKO'd it with Meteor Mash.
Battle Arena: Interesting idea, but it helps to train Pokemon specifically for it. All out attacking seems to be the best strategy here due to the 3 turn limit and the one judge who scores based on how many times you (tried to) use an attacking move. Latias was less than optimal here so I opted to try Swellow instead for a fast sweeper; this led to an amusing sequence where it was put to sleep by a Slowpoke's Yawn just in time for the next opponent, then prompty *won* a match it spent entirely asleep due to the enemy Shellder dicking around with Defense Curl then missing some shitty attacks like Supersonic. Opted for just one round here then moved on.
Battle Palace: Argh this place sucks. Hate the randomness, and even worse the turns when Pokemon just do nothing. My Metagross has a supposedly always-attacking nature and four attack moves and still wastes turns sometimes. -_- Finished one round due to the opponents using NFE crap then moved on. At least the BP here is nice, initial 4/5 on the first round as opposed to the 1 BP for starters crap that Arena/Pike/Dome pull.
Battle Pike: Got a scare first time when my *entire* team was frozen by a random status room... only for that to be the final room. Beat Lucy on the first try; Seviper sucked and Shuckle literally couldn't touch Metagross, but Milotic took some good luck. It somehow survived a *five* CM Dragon Claw from Latias, but opted for Ice Beam instead of Mirror Coat that turn, so I got the chance to finish it off. It would've eaten Metagross and Swampert alive if it had the chance, too.
Battle Dome: I like the Dome; with all matches 2v2 and only 4 matches per round, it's much faster than all the other places save the Pike with obscenely good luck. Got to Tucker on the first try and beat him handily; his Swampert used Counter against Latias for some inane reason, making it a free win. Next came Charizard, who had a 0% chance of getting past Latias ever. His other Pokemon was Salamence, so picking it instead wouldn't have helped either.
Battle Tower: Did this last, since it's pretty much identical to the DP version but slower to reach the leader and my Pokemon selection is worse. Still, I needed a third symbol to get access to the betting man as I hadn't beaten Brandon yet. Latias got haxed by Firepunch's 10% burn rate (later replays showed it would've barely survived otherwise, too ;_;) and fell to zam, but Metagross survived a hit and got in a OHKO, then Swampert went on to beat the next two Pokemon. I'd call surviving a Snorlax Body Slam with 2 HP left good luck, but 'gross would've finished it off anyhow.