Arlenon does not spawn on her own and is summoned with the Pearl of the Sky at Sky altitude, close to Space.
Arlenon hovers above the player(s) and shoots projectiles at them. Occasionally, she will stop to fire rings of Harpy Feathers before summoning Skyeyes to assist her in battle. Alongside this, she will try to trap the player by summoning a tornado and dashing into them. This tornado cannot hurt the player for 1 second upon spawning to prevent cheap hits.
While Arlenon is supposed to be fought at high altitudes, she can be lured anywhere in the world with no consequences.
Don't fight Arlenon near Space as the low gravity will greatly reduce your mobility.
Using a Unicorn Mount will allow players to get away from her dash attacks.