This is a guide for all the post game events. Please contribute by adding onto it and correcting possible mistakes.
Here’s a list of quests not done yet that anyone is welcome to write (this is not a comprehensive list, things will be missing):
Perfection Lab in Metchi Town, Perfection Base Mewtwo, and other stuff I am most likely forgetting.
1st Quest- The Timeless
First Quest Guide
After you beat the E4, go back to the cave south of Amphrite city where you battled Mew. The timeless will be waiting for you. Defeat all of them and battle their leader to become the 3rd Augur of the Torren Region and unlock other post game quests.
Recommended Levels: 85-95
2nd Quest- The Holon Region
2nd Quest Guide
After beating the timeless you will get a call from scientist club if you already finished the mission they give you in Koril Town. They ask you you to travel to Suntouched city’s Subway so you can go to Holon where you can obtain several deltas, the Regi Trio, their delta counterparts, Primal Regigigas. While going through the pyramid, you’ll find the Magic Carpet, the replacement for HM Waterfall.
Recommended Levels: 90-100
Delta Locations
3rd Quest- The Original Dragon
3rd Quest Guide
After getting a call from Orion, you head to his gym where he briefs you on his situation. He tells you that Taen is back in town and is gonna try to summon the Original Dragon once again. You head to the Perfection base where you find Reukra being berated by angry protesters including one green haired individual named Gail. He shows you his Zygard in a friendly spar and gives you a pair of Hiking Boots, the replacement for HM Rock climb.From here, go to Gaea Town and use the hyperspace hole inside the old gym. You will be transported to No Man’s Land. Go north and into the alpha ruins. At the end, find the ancient keyboard and type in “birth”. After your encounter with Taen, heal at a Pokemon center. From here, go to Utira Town Library and go to the far west wing. Talk to Orion and return to Dragon Ruins. After your fight with Taen, Zygard will start rampaging. You can catch it and then collect the stones for Zekrom and Reshiram. Then Taen leaves the friggen region to star in Pokemon Azurite.
Recommended Levels: 90-100
Optional: 4th Quest- NO DATA
4th Quest Guide
Go to the human calculator in Gaea town. Tell him to divide by 0 and watch your game crash. When you open the game again, hop onto the PikaTaxi and soar to the southeast of torren. You will find a buggy mess in the ocean, which say’s it’s “Gaea Town”. Head inside and battle MISSINGNO. Hitting it with physical attacks will have a chance to instantly faint your Pokemon. After finishing the battle with it, you will be sent back to Gaea Town.
Recommended Levels: 85-90
Optional: 5th Quest- Relic Song
5th Quest Guide
Find all the Mysterious Scrolls. They are located in: Koril town, Helios sewers, Whirl islands, Nasca town, Fiery caverns, Cave of origin (void gauntlet), Mist island, and Holon volcano. After getting all 8 scrolls, go to Route 5 and into a cave that requires you go use waterfall. Place the scrolls into slots that have a hole into them and find Meloetta at the end of your path. After battling it, you obtain it’s DNA and can now use Relic Song to open walls with it’s marker. You may also return to holon and go south to find an giant rock above a spire. Sing to it to reveal a path to Delta Meloetta. You can change it’s form by talking to the event tutor in No man’s land and giving it Relic Song.
Recommended Levels: 85-90
6th Quest: Healing Damian
6th Quest Guide
After obtaining the Hiking Boots (Rock Climb) during the Perfect Dragon quest and getting the Magic Carpet (waterfall) in Holon, go to route 5 and scale the waterfall. You will find a Hoopa portal back to the dream world there. When you get back to Erebus City in the dream world, you will see a rather chaotic cutscene, after which Adam will start talking to you and send you on a mission to catch a certain legendary. This will send you to Prion Site, and when you go west you enter the Nightmare Badlands. As you climb through the Badlands, battling as you go, eventually you will get to a little shack, before which a rather powerful trainer will accost and battle you. After you win, you catch the legendary, automatically get transported back to Erebus and fight Damian. Remember that you will not get a chance to heal, so heal before fighting Darkrai. NOTE: Remember where that shack is. you will want to go back there eventually in Quest 9: Diana’s Parcel.
Recommended Levels: 90-95
7th Quest: The Azure Flute
7th Quest Guide
After finishing the Original Dragon, Holon, and Dream World quests, go back to Perfection Base (near Black Market). Once you read the note, return to Amphitrite City to the cave where Mew and the Timeless were, and go through the Hoopa portal which you previously used to get to Giratina. Just follow the path the same way you did for Giratina, and on the way, various trainers and legendary pokemon will stop you. Eventually, you will get back to the Throne of the Hegemon, and Reukra will battle you, after which Arceus will be summoned which you can catch.NOTE: Arceus has Perish Song, so be very careful. Also, you cannot heal between battling Reukra and catching Arceus. Also, this quest must be finished before the elite 4 can be rematched I believe.
Recommended Levels: 100-110.
Optional-8th Quest:Rose Crater Quest
8th Quest Guide
After beating the timeless, go to Dreyan town. Head for rose crater and you will see professor’s aid, who dropped the magma stone in Infernal Base. Go to Infernal Base,Navigate through and you will see Heatran and Volcanion fighting. Navigate until you find a path blocked by magma, then equip the magma armor and go through the magma. After some navigation, you will find Groudon. Fight it and beat/catch it.Then head towards the exit, and you will encounter Heatran and Volcanion in a double battle, where you can catch one of them.Then exit the base.Talk to the aid for reward. Note:If you catch Heatran and kill Volcanion, Volcanion will appear in cave of steam. If you catch Volcanion and kill Heatran, it will appear in fiery caverns.
Recommended Levels: 90-95
Optional-9th Quest:Diana’s Parcel
9th Quest Guide
Requirements:Hiking boots,magic carpet,hyperspace hole.
After finishing the Azure Flute Quest, go in front of Selene City Gym,You will see Diana standing there.Talk to her and she will give you the parcel.Go to route 5, then dream realm.Then go to The place where you caught darkrai. After reaching there, you will see persephone.Talk to her, she will take the parcel and give you the masterball. This also allows you to be able to catch Cresselia as a roaming legend.
Go back to Selene City and talk to Diana.
Recommended Levels: 90-100
Optional-10th Quest: Save Audrey
10th Quest Guide
After healing Damian, you may go to where you fought Audrey in the Abyssal Cultist base located in Maelstrom 9. Dive there, and go through the cave known as the Deep Cavern. At the end of the water current puzzle, you find Kyogre confronting Audrey. You agree with Damian to help her, so he uses an escape rope with her while you distract. You initiate a battle with it, with Audrey’s Lugia helping you. If you want to catch it, it is recommended you kill Lugia. There are no consequences. From here, return to where you fought her in Whirl Islands. Go up the waterfall in the back and fight/catch her Lugia. Now you may go back to Erebus City, where Damian awaits you. He tells you that he is planning on turning a new leaf, and gives you his Shaymin if you agree to take it.
Recommended level: 105-115
Please note: Several of the contents are out of order.