User blog comment:Eeepzlala/Urgent SBB levelling/@comment-25421406-20140914222526

The 3 types of BB are Damage, healing, and support

The type you are missing is support, I.E. anything that does not heal or do damage (adding element to attack, increasing stats for x turns)

Leveling BB's is not as difficult as it sounds, and really best to just do it as you go through the main quest.

Things that affect BB chances:

1. Rarity of the unit

2. The success of the fusion (success, great success, or super success)

3. I believe the chances for leveling SBB's is slightly lower than normal ones

4. The current level of the BB

5. The type of BB (healing/support BB's are much harder to level)

6. Fusing in a unit that is the same unit as the one that you are leveling has about a 5x higher chance to level the BB (as in if you fuse a faerie into a faerie). This works for any rarity version of the unit, however higher is still better.

You can get BB gauges up to 8 off of using just junky 1/2 star units.

After level 8 BB/SBB, fusing 1 and 2 star units will not level a BB unless you get a great/super success. This would be the point where you want to use a frog.

Most SBB's will require the unit type of what was added to from the origional BB to level. As in if you have a healing unit (tiara for example) who's BB gauge heals for 3 turns and adds water element to attack, level her BB gauge takes support or healing units. Her SBB however adds a 12 combo water AoE on top of that healing, and it therefore only damage type units will level her SBB.

Also note that when picking units to fuse, if it has a chance to level the base unit's BB there is a green flashing icon on the picture that says "BB up?" Or if you look at a burst frog there is a red flashing icon that says "BB up!"