I checked the guide and it said you have to fuse it with another unit that has the same brave burst. Does that mean it has to be the exact same unit? How would you level up a rare unit or starter unit then? NinjaDiv6 - 4 years ago
There are 3 types of brave burst:
Match the brave bursts up and you will get a chance to level it up (it's random). It can be any rarity, from a 1 star to a 5. Keep in mind when you evolve the unit the BB level goes back to 1. coolmanx2 - 4 years ago
Above answer is accurate.
I feel I should add a couple things.
1. You also want to match element, much better chance of level up.
2. level 1-5 are reasonably easy, chance of level drops significantly from 6-10(10 is max).
3. They now have a new unit called "Burst Frog" when you fuse it into any unit it levels brave burst. bladejtr - 4 years ago
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