When you complete a battle and receive mutators, you need to think about what characters you want to give them to in Urtuk: The Desolation. These mutators are items that augment your character’s abilities, but they have a downside of taking away a chunk of their maximum health, which is difficult to heal. The adverse side effects are essential to consider because a character can hold three at a time. You can start to lower these negative effects by upgrading them.
To upgrade your mutators, you need to find two of the same ones and have them in your inventory. None of your characters can hold them. You may need to dismantle one of the items in your inventory to make room. When you have both of them sitting in your inventory, grab one of them, and drag them to the other. You should receive a popup verifying you want to combine to upgrade it. After confirming, you should have new, stronger mutator in your inventory ready for any of your characters to hold.
Now, if you want to upgrade it again, you need to find another mutator at the same level. You cannot improve a level one mutator with a level two, even if they are the same item. You need to have two-level mutators to upgrade them into a level three.
If there are mutators you don’t want to use anymore, you can dismantle them to acquire life essence. You need this resource to extract mutators from enemies after a battle, so consider this a viable option when you don’t want to use an item anymore.