Last Prism

The Last Prism is a drop from the Moon Lord.

There appear to be 6 beams that deal damage that rotate and get closer together as the beam charges, this takes approx. 4 seconds, each beam does damage once per second. This means without crits or damage amplification this weapon does 600 damage per second when fully charged. However due to the high mana cost (12 mana 6 times per second when fully charged is 72 mana per second) players will struggle to maintain the beam for more than 5-6 seconds. A Mana Flower is recommended for this weapon. The Last Prism cannot acquire the Mythical Modifier. The beam does not pass through blocks but can pass through platforms.

Unconfirmed: doesn't seem to be able to be reforged to "Mythical" or "Godly"

Trivia
This may be a reference to Touhou Project, where the character Kirisame Marisa, one of the main playable characters, developed a similar attack known as "Master Spark", and focuses it through a small wood and crystal device she made known as "Hakkero". The beam she fires is rainbow coloured in appearance.