Empress of Light

The Empress of Light is a Hardmode, post-Plantera boss. It is summoned by killing a Prismatic Lacewing at night in the Hallow. The Prismatic Lacewing will only spawn after Plantera has been defeated. Fighting the Empress of Light is completely optional and not required to progress, however, her defeat will reward the player with powerful weapons.

Behavior

 * The boss uses fast-paced multicolor attacks. She has two attack patterns: In the first stage, she will alternate between various attacks in which multiple projectiles home in on the player. In the second stage, she will fire projectiles across the screen in straight lines at various angles.
 * If she is fought during the day, all of her attacks will deal massive amounts of damage, killing the player instantly. If the Empress is killed during the day, she will drop the Terraprisma.

Tips

 * It would be wise to defeat Golem first, so the Cosmic Car Key will become available.
 * Not only does the Empress have to be killed during the day to gain the Terraprisma, but all damage she receives must be during the day as well. Therefore, it would be wise to start the fight as close to 4:30 AM as possible so that you take as little damage before daytime as possible (this can be done by using a bug net on the prismatic lacewing during the night, and then releasing it right before daytime).
 * Consider using a Bug Net to capture any Prismatic Lacewings when you see them, rather than killing them immediately. This will allow you to easily fight the Empress at a time of your choosing once you are prepared. Note that if the Prismatic Lacewing is released outside of the Hallow, it will immediately disappear.

Trivia

 * This boss was described as "a beautiful bullet hell" by Cenx before 1.4 was released.
 * She is similar to Skeletron Prime in that she gains increased damage during the day. However, Skeletron Prime does not drop items when defeated at daytime, unlike the Empress of Light.
 * The Empress of Light is one of the two new bosses added in the 1.4.0.1 update also known as the “Journey's End” update.
 * She and Plantera have the only musical instrument drops of any boss, with The Axe and the Stellar Tune having the same drop chance as well.
 * The Empress of Light is one of 5 bosses with exclusive music, the others being Queen Slime, Plantera, Duke Fishron and Moon Lord.