Here is the full list of all 15 Witch and Hero achievements.
Defeat Medusa.
Get 8000 experience in 1 battle.
Back-attack enemies 1000 times.
Win a battle despite Hero fainting 20 times.
Get 16000 gold in 1 battle.
Clear stage 20 with Hero fainting under 3 times.
Clear stage 19 without the Witch taking damage.
Clear stage 18 without using Holy Sword.
Increase your Sword, Shield, Boots, Fire and Storm levels to maximum capacity.
Clear all stages.
Clear Survival Mode.
Clear the bonus wave in the Tower of Trials.
Clear the Tower of Trials with over 60 seconds to spare.
Collect all dialogue with the Sales girl .
Achieve all trophies.