"Secret" Ascension Ending

Requirements:

• Don't choose certain Mythic Paths like Legend, Swarm-That-Walks, or True Aeon. Legend and Swarm do not work for story reasons (and due to Swarm not being able to complete the Act 5 research projects). Aeon can achieve ascension, but a True Aeon will receive a choice at the end of the game that is mutually exclusive with ascension.
• Enter the Threshold location on or between the 15th and 21st of Gozran (month IV), in year 4717. Technically, any year will work, but 4717 is the most likely window involving the least amount of crusade time skipping.
• Obtain Areelu's approval throughout the story (at least 5 out of a possible 7 approval points required).
• Complete all Mythic Quests for your path and obtain Mythic Rank 10.
• Complete all the required crusade research projects. Do not enable auto-crusade mode or you will fail this.
• Fully decipher the Lexicon of Paradox. The Storyteller's notes are not required, but collecting all 21 of them will allow you to bypass the Knowledge and Lore checks.
• Have at least 1 Fresh Nahyndrian Crystal from using a Midnight Bolt on a Demon Lord. If you have 2-4 crystals, the Commander and Areelu can ascend. If you have 5 crystals, Commander and companions can ascend. If you have 6 crystals, Commander, companions, and Areelu can all ascend.
  • Note: The Purple Stone Knife counts as a crystal, but you must obtain at least one Fresh Nahyndrian Crystal from a demon lord in order to unlock the corresponding research project.

Walkthrough

This walkthrough will guide you to the full ascension ending. Follow these steps during your playthrough:

Act 1

• Fight Deskari when he reveals himself, rather than taking the scroll. (+1 Areelu approval)
  • This is the first of 7 "Areelu approval" flags that you can use at the end of the game to persuade Areelu that her experiment was not a failure. You must achieve at least 5 out of the possible 7 approval flags.
• Pick up the Purple Stone Knife and the Midnight Bolt when you return to Market Square. The Purple Stone Knife counts as a Fresh Nahyndrian Crystal. Never sell or discard this item.
• (Optional) Pick the Trickster dialogue option in the Blackwing Library to unlock the Trickster mythic path. This will come in handy with Nurah during later acts. You do not need to play as the Trickster mythic path, just have it unlocked.
• Don't choose the Lawful Aeon, Lawful Angel or Neutral options when dealing with the Wardstone, as these will take the Purple Stone Knife away from you. (However, if you choose the Aeon mythic path, there is now an option for Aeons to get a replacement in Act 5.)

Act 2

• (Optional) Focus on making Nurah your ally. After Leper's Smile, enter Nurah's tent. Pass a Perception check to find a perfume bottle and confront her about it. During the Gargoyle attack event, find her in the northwest area just outside the command tent and pass another Perception check. After the Lost Chapel, confront her in her tent once more; choose the Trickster dialogue option to persuade her to join your side.
• During the Siege of Drezen, free the crusader, Yaniel. She will tell you of a secret path, and you must choose either the Neutral or Evil answer to her question. (+1 Areelu approval)
• (Optional) Spare Nurah after the boss fight with Minagho.

Act 3

• Complete the Studying the Sword of Valor crusade research project before the end of this act.
• Find the Lexicon of Paradox, Part One and the Midnight Bolt at Areelu's Lab. Keep it and accept its power. You will not be able to decipher it until you obtain Part Two later.
• Don't kill Suture. He is important.
• (Optional) At the end of the act, you have the option to give Part One of the Lexicon to Queen Galfrey. If you give it to her now, you must go to her aid during Iz in Act 5 to get it back. If you don't want to worry about that, keep it for yourself. Just be aware that this choice may result in her death. See Heart of the Fallen Land for more details about what happens in Iz.

Act 4

Alushinyrra

• Visit the Fleshmarkets and obtain Suture's freedom, either by buying him or by fighting Sarzaksys. Fighting Sarzaksys will trigger a huge battle with the other slave traders and several guards. You can make this battle significantly easier by killing each trader individually before you confront Sarzaksys. Be sure to buy what you want from them before you fight them.
• Do not show your Purple Crystal Knife to Shamira or she will take it from you.

Nocticula's Palace and Colyphyr Mines

• Go to Nocticula's palace and pick up Lexicon of Paradox, Part Two from one of the bookshelves (requires high Perception check). There is another Midnight Bolt here.
  • You can technically decipher the Lexicon now that you have both halves, but the Knowledge and Lore checks can be a bit tough. Best to save this for Act 5.

• When you meet Areelu, pass a Perception check and select the dialogue option "What are you doing here, Areelu? And with the Suture in tow." Then select "Why was that whole ploy with the lab necessary? You even sacrificed your servant, the Suture, for it." which will trigger another Perception check. Finally, select "Look at that, I actually provoked a reaction..." Doing all of this will allow you to discover that she cares about Suture.
• Areelu will then offer you power. First, speak to her to learn more rather than taking the power immediately. (+1 Areelu approval) Once you've exhausted these questions, you can take or reject the power she offers. 
• Be careful about accepting Nocticula's Profane Gift when going for the ascension ending. If you do, you'll need to pass a high Will check at the end of the act when you try to take the Fresh Nahyndrian Crystal. You'll lose her gift if you pass the check anyway, and we need that crystal, so make your own judgment on whether it's worth having those extra stats for two or three boss battles.
• Obviously, don't give the Lexicon to Nocticula. She will not give it back.
• While fighting Baphomet in the Colyphyr Mines, use a Midnight Bolt on him to create a Fresh Nahyndrian Crystal. You'll get a dialogue option to pick this up when the fight is over. If you chose to accept Nocticula's gift, you'll now have to pass a high Will check to fight Nocticula's control and take the crystal.

Act 5

• Complete the Studying the Unusual Crystal crusade research project.
• In Pulura's Fall, choose to stop Mutasafen (or, if you followed all the optional Nurah steps earlier in the guide, you can save the survivors and Nurah will stop Mutasafen for you). Kill and loot Mutasafen. If you are following the Angel Mythic Path, you can save the survivors because you already obtained the Records of Pulura's Stargazers research project in Act 3.
• You'll get two new crusade research projects. Complete the Records of Pulura's Stargazers research project. The Northern Lights project is optional.
• Complete the final quest for your mythic path to reach Mythic Rank 9. Mythic Rank 10 will be achieved automatically in Threshold at the end of the game. (+1 Areelu approval)
• Decipher the Lexicon of Paradox. You can do this now by passing a Knowledge World, Knowledge Arcana, Lore Nature, and Lore Religion check (all DCs in mid to high 30's), or you can bypass the checks during Threshold if you obtained all 21 Elven Notes for the Storyteller.

Nahyndrian Crystal #6

• At this point you should decide which type of ascension you want to achieve:
  • Commander ascends: Requires only one Nahyndrian Crystal. If you've followed the guide, you can skip the rest of this section and ignore all remaining crystals and midnight bolts.
  • Commander and Areelu ascend: Requires 2-4 Nahyndrian Crystals. If you've followed the guide, you should have 2 crystals (the Purple Stone Knife, and one crystal from Baphomet) and can skip the rest of this section and ignore all remaining crystals and midnight bolts.
  • Commander and companions ascend: Requires 5 Nahyndrian Crystals. If you've followed the guide, you should have 2 crystals and can skip the rest of this section. We'll obtain the remaining 3 crystals later.
  • Commander, companions, and Areelu ascend: Requires 6 Nahyndrian Crystals.
• If you are going for the full ascension ending, you need a total of 6 Nahyndrian Crystals. Crystal #3 will come from Deskari in Iz. Crystals #4 and #5 will come from round two with Deskari and Baphomet in Threshold. That leaves one more crystal that we need to grab. There are two ways to go about this:
  • Demon and Trickster paths can obtain crystal #6 from their mythic quests, by using a Midnight Bolt on either Nocticula or Socothbenoth.
  • Other paths must obtain crystal #6 by completing Nenio's quest More Than Nothing and using a Midnight Bolt on Areshkagal at the Enigma Pyramid Summit (do not use a bolt on the projection of Areshkagal that you fight before entering the summit). This crystal must be picked up manually from the ground after the boss fight.

Iz

• In Iz, you must go to the Temple of Stone Manuscripts first and kill Anemora. If you go to the crusader camp first, the "Key" Crystal will be destroyed and you will not be able to access the secret area of Areelu's Lab (thus locking you out of the ascension ending). Collect the "Key" Crystal in the northern room and the Glass Key behind a hidden door near the entrance.
• You can collect a Midnight Bolt from the basement level of the House.
• Use a Midnight Bolt on Deskari to receive a Fresh Nahyndrian Crystal - collect it via a dialogue option after the fight. You must kill Deskari in Iz (which results in him cleaving the land with his scythe and falling into the Rasping Rifts). Do not let him fly away. If he flies away, you will not face the Echo of Deskari in Threshold, and you will fail this requirement.
• See Heart of the Fallen Land for a more detailed guide to Iz and its consequences.

Return to Areelu's Lab

• See Empty Memories for a detailed walkthrough of the secret area of Areelu's Lab. Completing this area correctly will net you some more required approval points (interacting with the items in the correct order and taking the gloves, using the Vial of Magical Formula, and speaking to her about the ghosts, for a total of +3 Areelu approval points) as well as Areelu Vorlesh's Drafts.
• Complete the Areelu Vorlesh's Drafts crusade research project.

Ineluctable Prison

• Free or kill the Hand of the Inheritor. If you picked up his heart before the encounter, only give it back to him if he fully trusted you in previous acts.
• Don't leave after fighting the Hand - there's a hidden passage in the northwest corner of this area that leads outside the labyrinth (requires Perception check). Enter the hidden passage and complete some Athletics checks to clear rubble and defeat the Father of Worms.
• Backtrack along the hidden passage. Just before the entry back into the labyrinth, pass a Mobility check to jump across a gap and speak to the ghost of Hepzamirah. When offered the option, say "You shouldn't have put your faith in your father." Exhaust her remaining dialogue to learn a critical piece of information: that the archpriest/archpriestess of a demon lord has the power to summon their patron to their side.

Threshold and Ascension

• Enter the Threshold fortress between the 15th and 21st of Gozran (month IV). The year doesn't matter, so skip as much time as you need. If needed, you can use crusade events and repeatable projects to prop up your morale, which will eventually begin decaying once your banners turn red due to the general lack of demon armies and forts. 
• If you have collected all the Elven Notes for the Storyteller, the 21st "secret" note can be found on a table in Threshold. Pick it up, return to the camp outside of Threshold, and give it to the Storyteller. He will give you a Blank Page that allows you to decipher the Lexicon without skill checks. Decipher it now if you have not already.
• The battle with Imezlen is the "point of no return." Be sure to complete any remaining quests and ending requirements before this.
• After defeating the Echo of Deskari, create a save, as this is your final opportunity to do so and you're about to enter multiple battles and critical conversations leading into the ending.
• Speak to Areelu and exhaust all her dialogue, then fight her.
• After the fight, execute the dialogue with Areelu as follows:
  1. Pass a Perception check to spot Suture.
  2. Do not choose the "I've uncovered your plan!" option, as this will lock you out of convincing her to work with you.
  3. Select "Stop! Listen to me! You called me a failed experiment - but what if you're wrong?"
  4. You can select the option "I want to know. I want to follow the truth, no matter where it leads" for the "best" response, but options 1, 2, and 3 all appear to work. Just don't tell her you don't care.
  5. You can now use the knowledge that she cares about Suture to open up the opportunity to convince her.
  6. This is where the Areelu approval points come into play. You must provide at least 5 reasons for her to believe in you, one reason corresponding to each approval point earned earlier in the guide.
  7. Next, you must tell her you want to work together.
  8. Areelu will ask you to explain your plan. This is where the Lexicon and research projects come into play. Share your knowledge on each point.
  9. Tell her the secret you learned from Hepzamirah, and note that she is now the Archpriestess of both Deskari and Baphomet.
  10. Tell her what date it is and what that means, and ask her to summon Baphomet and Deskari.
  11. Finally, let her know you that have a Fresh Nahyndrian Crystal and/or a Midnight Bolt.
• You'll now battle both Deskari and Baphomet at the same time, with Areelu fighting on your side (though she has an unfortunate tendency for friendly fire with her spells). Use a Midnight Bolt on both demon lords. The crystals will be automatically collected for you.
• If you followed everything in the guide, you'll now have 6 Nahyndrian crystals, enough for full ascension for the Commander, your companions, and Areelu. Inform Areelu of the good news and enjoy your ending!