Wow this is so cool! I haven't played the Emerald Battle Frontier in a long time, but back when I did I was always looking for a thread like this. Probably won't get back into Emerald at this current moment, but I'll share the strategy I used to get through all 20 rounds of the Battle Pyramid or
140 floors which was my goal at that time.
EDIT: For anyone looking to tackle the Pyramid, I believe Level 60 is actually the optimal level. I explain why in this post
https://www.smogon.com/forums/threa...sion-and-records.3648697/page-13#post-8402323
I used 3 different teams (5 if you count different movesets) to get through the 20 rounds (Level 100, team for each round listed below). The IVs are not the best since I never bothered to learn how to breed properly or manipulate the RNG.
If I were forced to choose a single team to use for every round, I think it would be Alakazam (w/Thunder+Ice Punch), Slaking, and Blissey.
Alakazam @ Leftovers
Ability: Synchronize
EVs: 6 HP / 252 SpA / 252 Spe
Nature: Modest
IVs: 21/1/15/24/11/29
Psychic
Thunder/Ice/Fire Punch
Thunder/Ice/Fire Punch
Teleport
Teleport is amazing in the Battle Pyramid as it allows you to escape any wild encounter. However, it is still preferable to kill the wild pokemon when it's easy to do so as Teleporting does not increase your light. Before using Alakazam I struggled a lot with the wild pokemon in certain rounds which heavily drained my resources.
I chose the 2 elemental punches based on the wild Pokemon in that round. I don't exactly remember, but I think I chose Modest over Timid since I figured the speed was already enough for most things including Gengar, but now looking at Crobat in the database, maybe that wasn't such a good idea lol.
On a side note, does anyone know how exactly the running mechanic works in the Pyramid? I have always wondered this but could never find any information on it.
Slaking @ Choice Band
Ability: Truant
EVs: 6 HP/ 252 Atk / 252 Spe
Nature: Adamant
IVs: 28/24/30/8/17/28
Return
Earthquake
Shadow Ball
Hyper Beam
Slaking really shines in the Pyramid's 1v1 battle format where it's not hindered by the locking effect of Choice Band, and the wasted turn from Hyper Beam or Truant doesn't matter if you OHKO. It easily OHKOs a large number of wild Pokemon and trainers alike. On floors where it can KO all the wild Pokemon, I make sure to lead with it.
Blissey @ Leftovers
Ability: Natural Cure
EVs: 252 HP / 252 Def / 6 Spe
Nature: Calm
IVs: 19/23/31/15/30/30
Aromatherapy
Softboiled
Seismic Toss
Flamethrower
As everyone knows, Blissey is amazing in the Pyramid thanks to Aromatherapy, Softboiled, and its high HP stat. Bold is better but I used a Calm one since it had good IVs by my standards.
I learned about how good Blissey was from
Bozo and his YouTube channel BozoTheBear. If you're looking to get gold symbols I recommend checking out his channel as he has videos for each of the 7 facilities.
In his Pyramid video, he shows how to explore each floor systematically to find the warp tile. This eliminates the need to fight trainers to figure out which direction the warp tile is in. It is
never a good idea to fight a trainer when you can avoid them, as trainers are the only way you can lose in this place.
The other 2 pokemon I used were Salamence and Starmie.
Salamence @ Choice Band
Ability: Intimidate
EVs: 6 HP / 252 Atk / 252 Spe
Nature: Jolly
IVs: 14/27/31/19/13/28
Earthquake
Aerial Ace
Brick Break
Rock Slide
Intimidate is really nice as it halves the random encounter rate if your lead pokemon has it and is 5 levels higher than the wild pokemon, which makes getting through the round much less annoying. I personally prefer Adamant over Jolly and I have an Adamant Salamence with much better IVs but sadly I messed up its EVs which can't be undone at Level 100.
Starmie @ Leftovers
Ability: Natural Cure
EVs: 6 HP / 252 SpA / 252 Spe
Nature: Hasty
IVs: 13/21/27/26/23/23
Surf
Psychic
Thunderbolt
Ice Beam
Natural Cure is nice in the Pyramid for status conditions and Starmie is a better special attacker than Alakazam overall, so I use it whenever I don't need Teleport. Timid is obviously better than Hasty but I am just that lazy with breeding lol.
Here are the teams I used during each of the 20 rounds, copied from an old notepad file that I fortunately never deleted. Lead pokemon varies by floor and elemental punches vary by round, but I didn't get that specific in my notes. I used Expert Evan's Wild Pokemon Guide to decide all of this.
Round 1: Salamence, Starmie, Blissey
Round 2: Salamence, Starmie, Blissey
Round 3: Salamence, Starmie, Blissey
Round 4: Salamence, Starmie, Blissey
Round 5: Slaking, Starmie, Blissey
Round 6: Slaking, Starmie, Blissey
Round 7: Alakazam, Slaking, Blissey
Round 8: Alakazam, Slaking, Blissey
Round 9: Slaking, Starmie, Blissey
Round 10: Salamence, Starmie, Blissey
Round 11: Salamence, Starmie, Blissey
Round 12: Salamence, Starmie, Blissey
Round 13: Alakazam, Slaking, Blissey
Round 14: Salamence, Starmie, Blissey
Round 15: Alakazam, Slaking, Blissey
Round 16: Alakazam, Slaking, Blissey
Round 17: Alakazam, Slaking, Blissey
Round 18: Slaking, Starmie, Blissey
Round 19: Salamence, Starmie, Blissey
Round 20: Alakazam, Slaking, Blissey
I know this is a long post but hopefully this is helpful for anyone looking to either get the gold symbol or complete all 20 rounds. I've attached a picture of my record below. (retail)