The cool part about Remnant 2 is that the world you enter for the first time after Ward 13 can be completely different for every player. Based on the order of your world generation, you'll also meet different NPCs and trigger different dialogues. Each region also has some exclusive craftable items.
Yaesha is one of these regions, and you can craft a new armor set here at the Bloodmoon Altar using an item called Blood Moon Essence. You need to be in a specific environment to get this item, which makes it quite rare.
How To Get Blood Moon Essence
If you want to get Blood Moon Essence, the first thing you'll need is the Yaesha region unlocked. You can only get and use this item in this region. Once you're in the region, you'll need to get lucky and have a Blood Moon active. When this happens, the entire area's color goes a bit orange and you can also see the moon in the sky.
When these conditions are met, you can go around the different areas of Yaesha to find some pink flying orbs. These orbs will usually start going up when you're near, and you won't be able to get them after a while. Shoot the orb with any kind of bullet once and you'll get the Essence in your inventory after a few seconds.
Getting a Blood Moon can be rare, but there's a trick that can help you get it on command, discussed below.
Once you've found an area with two or three of these orbs and farmed them, you need to look for a yellow portal that takes you to a different part of Yaesha. Simply use the portal to get to another region and then go right back. Head back to the same location where you found the orbs and they'll respawn.
This lets you farm them as many times as you want without touching the Checkpoint crystals and respawning all the enemies. The enemies don't respawn if you enter another area and then come back.
How To Get Blood Moon
Blood Moon is a mechanic that can only be encountered in Yaesha, and it's useful in a couple of other scenarios apart from farming Blood Moon Essence. To get Blood Moon on command, you first have to unlock another region apart from Yaesha and Ward 13.
If Yaesha is the first region you started in, you'll have to progress until you get to the Labyrinth. Once you have a second region, simply use the Checkpoint crystal to go to any part of a different region and then teleport back to Yaesha. This resets the environment in the region and you'll be able to encounter the Blood Moon eventually.
Keep in mind that this trick doesn't work if you teleport to Ward 13 and then back to Yaesha.
The best way to tell if you have a Blood Moon is by teleporting to an open area like The Forbidden Grove or Imperial Gardens. Move around in the area and you'll see the obvious change in the color. You can also look in the sky and locate the moon if it's not blocked by trees.