Celestial Sigil

Summoning the Moon Lord directly means you never touch the Lunar Events again. No pillars, no shield grinding, no travelling across the world to find the last one. For anyone farming him for drops that is the difference between a short loop and an evening, which is exactly the problem the item was added to fix.

He does not appear on the spot. There is a delay after you use it, which is enough time to get back to your arena, drink your buffs and be pointing the right way when he arrives. Use it before you are set up and you will still be scrambling when the fight starts, so treat the wait as your preparation window rather than an inconvenience.

The blocker list catches people out regularly. Golem has to be dead, nothing else can be alive or invading, and that includes the Pumpkin Moon, the Frost Moon and the Old One's Army. The Mysterious Tablet at the dungeon entrance also cannot be on anyone's screen. In multiplayer that last one is the usual culprit: a teammate standing near the dungeon quietly stops the summon from firing and nobody can work out why.