Most Dragon Ball Z games have plenty of characters and Burst Limit is certainly one of them. There are loads of unlockable Dragon Ball Z characters. To unlock your favorites, all you need to do is complete some key chapters

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throughout a particular story sequence.
Unlockable Characters in Saiyan’s Saga:
Here is a list of characters, which can be unlocked by playing through the Saiyan’s story sequence. You can unlock characters only after completing a particular chapter:
1. Raditz: Finish Chapter 1 to unlock this character
2. Saibamen: Beat Chapter 3 to unlock Saibamen
3. Nappa: Finishing Chapter 5 allows you to unlock this Dragon Ball Z character
4. Kaioken Goku: Beat Chapter 7 to unlock this DBZ character
Unlockable Characters in Cell’s Saga:
You can unlock your favorite characters through Cell’s story sequence. Finishing certain chapters helps you to unlock any character:
1. Android 18 and Super Saiyan Vegeta can be unlocked if you finish Chapter 2
2. Unlock Piccolo Fuse and Imperfect Cell by completing Chapter 4.
3. Trunks and Super Saiyan Trunks can be unlocked by finishing Chapter 7.
4. Teen Gohan can be unlocked after you complete chapter 1 of Cell’s Saga.
5. To unlock Android 17 finish Chapter 3.
6. Unlock Perfect Cell by completing Chapter 12.
7. Beat Chapter 6 to unlock Semi-Perfect cell.
8. Finish Chapter 18 to unlock Super Perfect Cell.
9. Complete Chapter 13 to unlock Super Trunks.
10. To unlock Super Saiyan II Gohan finish Chapter 19.
11. Finish Chapter 10 to unlock Super Vegeta.