Starting Part 3: Recruit old companions, merge causality, then restore the map and unlock classesMinor spoilers
Find green map markers to recruit old allies and spend 300 shards per merge. Follow with map repairs, army editing, and temple quests.
Original video: Part 3 overview: Merge Causality, map resources, and unlocking Divine and Master classes | Bilibili creator Xiaoma Ye Hen Mang De
Find green map markers to recruit old allies and spend 300 shards per merge. Follow with map repairs, army editing, and temple quests.
Recruit old companions before merging causality
When free movement in town becomes available in Part 3, green map markers show old companions you can recruit again. Recruit them first, then return to the obelisk to Merge Causality for 300 Karma Shards each time.
For example, if 
Sirocco trained swords in 
Leda's story and spells in 
Theodora's, merging in Part 3 takes the higher results for stats, abilities, and skill proficiency, retaining class mastery abilities too. Strengths developed across routes come together in one character.
Map repair supplies and army editing in the main city
Many map locations are damaged in Part 3. Repairs require vegetables, fish, and other supplies. Decide which road to restore before planning your gathering.
You can initially send out two armies, later increasing to five. Each holds up to eight people and does not need to be full. If you assign someone incorrectly or want a different formation, have the army you want to change act at the main-city location to access army editing.
Gather the Keys of the Diadem before Divine exams
Heaven's Crown Temple opens on March 6. Collect five 
Key of the Diadem from dungeon chests, then open the temple doors to unlock eight Divine classes. Actual reclassing still takes place at the capital's exam office.
For Divine weapon proficiency requirements, meeting one listed option is enough. You do not need to max every weapon shown. However, the success rate must reach 100% to certify, so raise your target proficiency first. Labyrinth chests also contain permanent stat boosters for Strength, Movement, and other stats, making them worth gathering along the way.
Main-sanctuary trials unlock Master classes
After restoring the main sanctuaries of six temples, accept temple trials from the attendant. Completing them unlocks the corresponding rewards. The destinations are the main sanctuaries reached by teleporting from temples in town.
Part of unlocking 
High Savant requires visiting the priest on the left in 
Jurah's main temple to receive the 
Fimbulvetr Night scroll. Learn the spell, then extinguish the fire in the Great Cave of Iapetos. Prepare the scroll and spell before traveling to clear the obstacle.
