Location: Artorius Throne, located behind the wind room on Artorius Throne. It’s the second elemental room you find. To open the locked door, simply use wind dash at the windmill (3).
Recommended Level: 75- 80
Recommended time frame: Before the final battle
Property: Winged, Dragon
Have your partner armatize with Lailah (it weak against fire). For you, simply armatize with Mikleo and use these attacks
Saint’s arrow => Blistering Fang => Six Falling Stars
It has a lot of HP, so the battle may take a little bit of time. It’s easy though.