User blog comment:VJ3oy/Which Unit do i need to upgrade the BB LVL of :/@comment-62.46.168.51-20141113181900

You lvl a attack bb with a other unit that has an attack bb.

Kuda has an attack BB so you need units with an attack BB, the best way to farm attack BB units are the missions on the first map Mistral (Adventures Prairie).

To get Support units I visite the Magutagal Wetlands in Mistral on the first mission you can get 1-4 Harpys.

The best way to geht heal units is the second mission in the blood forest in St. Lamia