If Androxus tries to flank and kill you, be careful where you shoot. If he uses Reversal, you can try to shoot behind him and use splash damage to kill him since reversal only takes damage from the front and Androxus can't shoot while in Reversal.
Once an Andro tries to flank you, you should try to get one or two shots on him, then use your seedlings. He will most likely use reversal which gives you time to escape. This works best if Andro's escape ability is on cooldown (after he has flied)