The Shadow Sphere is a Hardmode summon weapon dropped by Dusking. It summons a slow circling Shadow Sphere that fires Crystal Shadow projectiles at nearby enemies, which inflict the Shadowflame debuff. The summoned Shadow Sphere inflicts Minion damage, but is different from traditional minions in that it does not take up a minion slot, and does not follow the player.
As the Shadow Sphere does not count toward the minion cap, it will not cause any traditional minions to despawn; though summoning a second Shadow Sphere will always cause the first to disappear, even if the player has Minion bonuses.
Its best Modifier is Ruthless. The Mythical modifier provides the widest array of stats bonuses, but these primarily affect the initial summon rather than the resulting minion. Additionally, Minions cannot deal critical hits. The only significant advantage a Mythical Shadow Sphere has over a Ruthless one is knockback.