Saros Possession

Saros Possession is a craftable post-Moon Lord summon weapon and the direct upgrade to Sirius. It summons a spinning radiant aura around the player that fires two homing flares towards enemies. Homing radiant orbs will occasionally be summoned from a random position near the aura, alongside a wave of three flares. Summoning the Saros Possession will consume all remaining minion slots, with the number of slots consumed increasing the damage of both the flares and the radiant orbs.

Trivia

 * The sprites for both the staff itself and the minion it summons are references to The Radiance, a boss in the video game Hollow Knight.
 * A saros is a period of roughly 6,585 days, which can be used to predict eclipses.