The Armored Core 6 Moonlight Blade is a more futuristic take on the famed greatsword that FromSoftware likes to put in each of its games. You might remember hauling it from a mound of maggots in Demon Souls, defeating Ludwig in Bloodborne to get it, or, more recently, doing the entire Ranni quest in Elden Ring.
Thankfully, getting this "light wave blade" isn't as elaborate in Armored Core 6, though to actually extract it you will have to defeat the game's hardest boss—no one said it would be easy. So, here's where to find the Moonlight Sword in Armored Core 6 and extract it to bolt onto your beloved mech.
Where to find the Moonlight Sword
You can get the Moonlight Sword—known in-game as IA-CO1W2: Moonlight—from one of the hidden chests concealed throughout the game. The chest-in-question is found during the Reach the Coral Convergence mission in Chapter 4, so it requires a fair bit of progress into the game. After you fight the Arquebus squad, you'll have to cross a stretch of water via a large ruined bridge, where you'll be attacked by an autonomous grinder wheel.
Once that's destroyed, head to the far end of the bridge and look down to see four more grinder wheels surrounding a chest containing Moonlight. These wheels are very annoying to fight in the open area, so your best bet is destroying them in the initial salvo, or just hop down to quickly grab the chest and take off before they can properly attack you.
Now that was the easy part. In order to actually get Moonlight, you need to finish the mission, and that requires facing the Coral Convergence boss: the IB-01: CEL 240, or Ibis, as it's generally known. This is definitely the hardest boss in the game due to its speed, hard-to-dodge attacks, and all the little lazer drones it keeps firing off.
If you're banging your head against the wall, I recommend double miniguns to wear him down, and two shoulder-mounted VE-60SNA Stun Needle Launchers, since they deal an absurd amount of damage. Once finished, the next time you return to base you can equip Moonlight in Assembly.
