Lord of Creation achievement condition of unlocking is having all endings new game+ clear data on different individual slots, at least that`s what i saw mentioned online on numerous occasions, i got it after watching credits on the last remaining ending even before i made a new game+ save.

Also worth mentioning that although True Demon Ending is technically dlc content and does not have an achievement it is still required for the Lord of Creation to unlock (or so i heard)

I strongly advice you to do savestates for endings on new game+ with merciful difficulty as you can finish the game from start to finish in a few hours using your late game demons from compendium.

The game utilises hidden points and flags system to determine which ending the player is going to receive. All endings except TDE has a number of hidden points and flags which player can trigger throughout the game, Flags is much more important than points, as points system decides the ending only if all flags of multiple endings is triggered. Shijima, Yosuga, and Musubi endings have 2 flags each, Neutral and Freedom have 3 each. For the true demon ending you`ll need to complete the Fifth Kalpa dungeon before entering tower of kagutsuchi, as the first time you enter it it will lock you onto whatever ending you are going for at the moment, also if this ending requirement is triggered it will lock you out of all remaining endings, so if you plan on doing Maniax/Chronicle content, but don`t want to trigger this ending just make sure to not kill Metatron in the Fifth Kalpa.

Each key dialogue options containing flags for the endings is stated in this guide below. If dialogue option is not mentioned in this guide, then its either gives hidden points or does nothing.

As hidden points doesn't matter in terms of this guide and there`s just so many of them i will not mention them further.

There will be 3 moments in the story in which you`ll need to collect first flags of Yosuga, Musubi, and Shijima. Collecting just 1 flag of multiple Reasons does not lock you out of any of the endings, so you do not have to make split save at those choices and can just collect them all.

Up until you reach Assembly of Nihilo you can choose whatever, dialogue options only contain hidden points, The first flag appears after you complete Assembly of Nihilo and teleport back to Ikebukuro, in the entrance of Mantra HQ will be a cutscene in which Chiaki will reveal the Reason of Yosuga. You`ll need to respond "Yeah i get it." to her question to receive first Yosuga flag.



Second moment when flag can be collected will happen after Completing Obelisk, when you teleport to Asakusa you can speak with Hijiri and tell him to teleport you to where Isamu is, after completing a small dungeon and killing Specter boss there will be a cutscene in which Isamu will reveal the Reason of Musubi. This time you need to select "I can relate."



Third moment and last Reason flag we can collect without making separate saves comes not long after, right after you triggered Musubi flag you can explore new building in Asakusa, there Hua Po demon will tell you that Hikawa was seen near Manta HQ, teleport to Ikebukuro and at the stairs of Mantra HQ will play a cutscene in which Hikawa will reveal the Reason of Shijima. Answer "Actually, i do."

First separate save you`ll have to make will be in the Yoyogi Park, right after Sakahagi boss fight will be dialogue with Yuko, in which you`ll hand over Yahiro no Himorogi to her, and Aradia will appear. You`ll need to make a separate save before this dialogue as answers to her questions contains multiple Neutral/Freedom flags, and in case you choose both Freedom flags you`ll lock yourself out of some other endings.

For now we`ll be choosing Neutral flags as picking them up does not lock you out of other endings except Freedom. For Freedom ending you`ll have to return to this save.

Choose "...i`m terrified." for both questions to get Neutral flags

At the Amala temple after completing black, white, and red temples you`ll need to make a separate save before going to opened up location in the middle of the temple, from this save you`ll be able to complete Isamu's ending later.

This choice will not appear if you missed his first flag.

For now choose "No way." this will reject the Musubi Reason allowing you to get other endings.
"All right." option will lock you in Musubi ending, and if later second flag of different reason is triggered will result in hidden point system deciding the game ending.

Right after completing the Amala temple you need to teleport to Mifunashiro, there right before you go into the third sanctum will be an S-terminal at which you`ll need to make third save state, from it you will be able to get Chiaki`s ending.

This choice will not be present if you missed her first flag.

Choose "You're misguided." to reject Yosuga.
Choosing "I see your point." option will lock you in Yosuga ending, and if later second flag of different reason is triggered will result in hidden point system deciding the game ending.

After beating Mithra in the Diet building save in a different slot to make a save state for Hikawa`s ending.

This choice will be present no matter what, but for Shijima ending you`ll still need his first flag.

In the cutscene Hikawa will ask you to stand aside, choose "Can`t do that." option, it will lock you out of Shijima ending, allowing Neutral and TD endings to be received.
Choosing "Fine by me." will trigger his second flag locking you either in Shijima, or whatever ending that also has 2 flags and wins by points.

After Hikawa`s dialogue and Samael boss battle you will receive Yahiro no Himorogi which will can be used to start Tower of Kagutsuchi - game`s final dungeon, If you're aiming to get true demon ending you`ll have to make a separate save at this point, and complete Fifth Kalpa before entering Tower of Kagutsuchi as doing so lock`s you in TD ending no matter how many flags of any Reason was collected.

For Neutal you can simply go to Tower of Kagutsuchi and Finish the game, as entering it lock`s in current ending, and without second flag of any Reason it`ll be Neutral. Kagutsuchi has unique dialogue for different endings you`re going for when you enter the tower for the first time. so you can check at this point if you`re doing everything correctly.

After completing Neutral you can return to previous saves and finish them.

For Musubi answer "All right." to Isamu in Amala temple, and then choose every single dialogue option the same as in the Neutral playthrough.

For Yosuga answer "I see your point." to Chiaki in Mifunashiro and then choose every single dialogue option the same as in the Neutral playthrough.

For Shijima answer "Fine by me." to Hikawa in the Diet building and finish the game.

For Freedom ending choose "i can take it" to both Aradia`s questions in Yoyogi Park, then deny other reasons and choose "Can`t do that" to Hikawa in the Diet building since this counts as third freedom flag you can just finish the game.

Lord of Creation will drop after you`ll watch all endings and have individual new game+ clear data for every ending.

Here's is my save file, it contains individual saves before each ending and also each ending new game+ clear data, as i said before at the start of this guide there are content from payed DLC's in the save file, so it most likely won`t work if you do not have those installed.

Here's a quick description of the save slots before the final boss: (i mostly sure its right)
1 - tde
4 - yosuga
5 - musubi
6 - shijima
7 - neutral
8 - freedom

And here's the download links:
Mega [mega.nz]
Google Drive [drive.google.com]
Github [github.com]

DLC's used :
https://steamproxy.com/steamstore/app/1497870/Shin_Megami_Tensei_III_Nocturne_HD_Remaster__Merciful_Difficulty/?snr=1_16_16_18_1059&curator_clanid=40117418
https://steamproxy.com/steamstore/app/1502940/Shin_Megami_Tensei_III_Nocturne_HD_Remaster__Chronicle_Pack/?snr=1_16_16_18_curator-tabs&curator_clanid=40117418
https://steamproxy.com/steamstore/app/1502000/Shin_Megami_Tensei_III_Nocturne_HD_Remaster__Maniax_Pack/?snr=1_16_16_18_curator-tabs&curator_clanid=40117418
https://steamproxy.com/steamstore/app/1527660/Shin_Megami_Tensei_III_Nocturne_HD_Remaster__Mercy_and_Expectation_Map_Pack/?snr=1_16_16_18_curator-tabs&curator_clanid=40117418

If you have found any mistakes in this guide, please write them in the comments.