The Lunar Portal Staff summons a Lunar Portal at the position of the cursor. After a few seconds it starts to attack enemies within a 60-tile range of itself. The portal acts as a turret and disappears after 2 minutes.
The attack sweeps in the direction of the enemy, and with a decent Modifier that applies to Knockback, prevent enemies from approaching or force them into traps.
It has trouble hitting fast targets, and is most effective against slower mobs and large bosses which follow a predictable movement pattern.
Buffs to summons, such as those with Stardust Armor, apply to stationary summons. They do not count toward summon limits.