Unlock “Unknown History” Secret Mission and Ending
After completing the “Warrior From The Demon World” Time Vault chapter and viewing the normal ending sequence, the story completion (under player stats) will still not display at 100%. That is because there is another secret mission called “Unknown History”. To unlock it, you must complete a series of quest lines in the five Time Rifts (the large flying objects over Conton City) to get five Distorted Time Eggs. Give the eggs to the Supreme Kai near the Time Vault, then speak to Trunks. Here are all 5 Quest Lines in detail. If you cannot progress in a quest line, it is because your power level is too low or you need to wait between fights and do something else. It is recommended you are around Level 75 when attempting all of this. Successfully complete the indicated tasks to earn all five Time Eggs:
1. Hercule’s House: Complete all six Sayamen quests in Hercule’s House. When you enter the house area, turn right to find them in the courtyard. If they are not there, you must talk to them in the Resort District/Kame House first.
You can ignore Hercule’s quests, as only the Saiyamen quests matter.
2. Capsule Corporation: Complete all four Vegeta fights. He is standing in the left side of the area. If he does not offer you a fight, your level is too low and you must gain a higher level.
3. Guru’s House: Defend Guru’s house ten times (complete ten of Nail’s quest in the House area). After accepting the first quest in this area, you will sometimes see a notification in the top right corner of the screen that the house is under attack. When this happens, Nail will offer you a new quest there. In those quests, you must collect some Dragon Balls. There are six parts to the quest. After completing all six, they reset to Part 1. You must keep doing these quests until a total of ten have been completed. Then, speak to Guru for him to power up your Shenron Wishes.
4. Majin Buu’s House: Feed Buu until he has six children.
5. Frieza’s Spaceship: Complete all 17 quests in Frieza’s Spaceship. Some of the quests will not appear right away and you must leave. Let some time go by and complete some other fights (for example, Parallel quests). After a few other fights, you should see a notification in the top right corner that a new mission is available in the spaceship. You also need to have a higher power level before some quests become available.