To find the final Wrath Shard, use the Serpent Hole to reach The Ashlands. Take a right out of the small cave you are transported to, and continue down the path until you reach the area with the three monsters hanging from the ceiling with the wire that you can jump to in the middle. Jump on the wire to the left of the monsters, and continue left. Grab the growth, and pull yourself up into the opening. Then, look to the right and up. You should see an orange object you can use to grab with the chain. After using the chain, walk slightly further into the area to find a chest with the last Wrath Shard.