There's a nice angel graffiti next to the landing place door.
What should I do?
Position Fia directly in front of the graffiti to make her look like an angel with the halo and all.
Go into the position facing left. Then come a little out from the wall. Try to shift the position until you get the achievement.
Achievement help
This is the guide for "Sera-fia" achievement in Old Skies. At Nice Game Hints you get hints even on the achievements. Click the big button below to get your first hint on getting this achievement.