Dragon slayed... that had to be the easiest Hard achievement ever. Buy armor upgrades and save your elixirs because armor upgrades heal you to full health as well as raising its max. One weapon upgrade also helps. Once you get ~level 12, buy the next Divine Sword you see and just hope that the dragon appears before you are forced to use it on a basic enemy.
 "Trigger Knight"){kind=icon}
 "Snakes On A Cartesian Plane"){kind=icon}