How Concealing Omen work in Horizon Forbidden West

gamepur.com:

Sometimes you want to take the stealthy approach when confronting the machines. After all, brute force isn’t always the answer. It’s for this reason that stealth items like Concealing Omen exist, but what are these strange fungi? Here is how Concealing Omen work in Horizon Forbidden West.

You may have noticed these large mushrooms in the caves around Chainscrape during your time in the area. If you completed the Deep Trouble or Bristlebacks side quests, you will have seen these mushrooms sprinkled throughout both of the caves. This fungus is designed for stealth and is used to keep you out of sight of the machines.

To activate Concealing Omen, walk up to one of the fungi and hit it with either your spear or an arrow. This will cause it to spray out a blue mist in the area around it. While in the mist, you will be hidden just like you would be if you used a smoke bomb or hid in tall grass. When the smoke starts to disappear, walk up to the fungus and hold the triangle button to reactivate the smoke. You can keep doing this until you decide to leave the smoke area.