I just can’t do it
jab blanka balls, punish unsafe balls with ex tatsu or ultra 2 (?), sweep electricity, if you corner blanka stay a good bit away to punish rainbow rolls.
Consult the ken or blanka forums for more detailed info, and keep in mind beating blanka is more of a player matchup than a character matchup, so study the habits and patterns of the opponent to counter. Blanka can be played extremely gimmicky so you have to keep those in mind and play really solid so you don’t get cheesed out.