Phantasm

Phantasm is a hardmode boss in Exxo Avalon. The boss is only summonable in the Hellcastle, which is a hardmode structure that generates upon world creation. In order to summon it, you must craft an Ectoplasmic Beacon with 15 Ectoplasm, 10 Chlorophyte Bars, and 8 Solarium Stars at the Library Altar in the Library of Knowledge inside the Hellcastle.

Boss Phases
In its first phase, Phantasm will fire a spread of Ghostflame projectiles, which inflict the Shadow Curse debuff at a 1 in 3 chance.

In its second phase, Phantasm will stop, charge, and fire a sweeping laser similar to the Moon Lord in 1.3.

In its third and final phase, the boss will instantly stop, relocate to the center of the Library of Knowledge, and begin to frenzy attack the player(s). It will fire a spiral spread of Ghostflame projectiles, then fire four sweeping lasers.

Drops
Upon death, Phantasm has a 1 in 15 chance to drop the Vampire Teeth. It will also drop 1 Ghost in the Machine on every kill.