This achievement is unlocked after completing the first campaign, which is for the blue dragon.
Level 1: Go fly around and destroy buildings to complete the level
Level 2: Go find a few towns and destroy them using the fire mechanic, while taking out archers with the longer range shot before entering. The goal is to kill 75 people so a lot of the homes have people in them and once you get to 75 the level will end.
Level 3: Fly to the right after the first town, hugging the coast. You will see the giant sphere outline. While it says you should get the rune first, you can skip the rune and fly to the very top of the sphere. Peek your dragon through the barrier and take out all nearby archers while you are out of there range. To complete the level you only need to destroy the castle, so if no more archers are in range of the castle you can destroy it with fire, completing the level.
Cheers on your game completion and 10 TSA. I doubt there will be any updates since this has sat 5+ years with no changes.