The greatest champions not in lane to counter Akshan include Tristana, Ziggs, and Jinx. These champs are all great at countering Akshan with win rates over 65%. Even if these Akshan counter picks are not used in your lane, it's not smart to choose them into one of these matchups. They will most often crush Akshan.
Conversely, if the enemy team brings either Wukong or Trundle, Akshan mains should strongly consider picking them, as they easily beats these champions with win rates over 54% against both ofthem.