The Moonlight greatsword, a staple of FromSoftware games from King’s Field to Demon’s Souls to Elden Ring, returns in Armored Core 6: Fires of Rubicon as a secret weapon, one that you won’t find until late in the game. But the Moonlight sword — or as it’s officially known in Armored Core 6, the IA-C01W2: Moonlight light wave blade — is a powerful, useful melee energy weapon that’s worth picking up.

Here’s how to find the longrunning Easter egg Moonlight sword in Armored Core 6.

Where to find the Moonlight sword in Armored Core 6

Players can find the Moonlight sword in the seventh mission of chapter 4, “Reach the Coral Convergence.” After defeating rival ACs G3 Wu Huahai and V.VI Maeterlinck, players will head toward a destroyed suspension bridge, where they’ll be attacked by an Autonomous Grinder Wheel. Below that bridge are more grinder wheels, and at its terminus, players will see the container that houses the IA-C01W2: Moonlight light wave blade.

There’s just one catch…

How to get the Moonlight sword in Armored Core 6

The “treasure chest” containing the Moonlight sword is guarded by four Autonomous Grinder Wheels. Destroying one, while it’s unaware, is easy with a grenade launcher or bazooka, but the rest will be a hassle.

The alternative to fighting these four spinning saw blades (the Armored Core 6 equivalent of Dark Souls’ infamous Wheel Skeletons), is to simply drop down, grab your loot, and boost away.

Image: FromSoftware/Bandai Namco via Polygon

Grabbing the Moonlight sword is the easy part. You’ll need to defeat the level’s boss, Ibis Series CEL 240, to make the IA-C01W2: Moonlight light wave blade part of your weapon collection.

When you do, you’ll be treated to the left-hand sword, which is described as a “Light-wave blade developed long ago by the Rubicon Research Institute. Fuses laser and pulse technology to accompany slashing attacks with waves of light. Charge to increase output, emitting larger waves of light.”

Armored Core 6 Moonlight sword stats

Here are the sword’s stats:

Image: FromSoftware/Bandai Namco via Polygon

And here’s what the Moonlight light wave blades attacks look like in action:

Of course, the Moonlight sword’s late-game ability isn’t a negative. Armored Core 6 features multiple new game-plus playthrough opportunities, and you may find the IA-C01W2: Moonlight light wave blade helpful in taking down the AH12 HC Helicopter and AA P07 Balteus a second or third time.