The Fissure of Malice is a Malignant Tunnel that you can find in the Fractured Peaks, being one of the 6 new dungeons introduced in Season of the Malignant.
Clearing this dungeon full of Malignant enemies has a good chance of getting a few Caged Hearts, which were also added during the Season.
When you explore this Malignant Tunnel, you will eventually encounter a Malignant Bloodlord named Myraleth who you must slay.
Fissure of Malice Location
You may find the Fissure of Malice around the Frostbite Trails, which is located in The Pallid Glade (Fractured Peaks).
The Fissure of Malice can be reached by heading north from Nevesk or by making your way south from Nostrava.
Fissure of Malice Objectives
1) Slay the Malignant Ghouls (2)
Upon entering the Fissure of Malice, you will be in the Forsaken Tunnels and will have to search for 2 Malignant Ghouls.
Once you find the Malignant Ghouls, they will need to be killed before you can proceed to the next area to fight the Malignant Bloodlord.
Both Malignant Ghouls can be found in the Forsaken Tunnels and will often be far away from each other, making it necessary to explore a bit.
2) Slay Myraleth, Malignant Bloodlord
Myraleth can be found nearby and once you get within range; it will begin attacking you right away and this enemy can be a bit annoying.
It has a habit of teleporting around the area and will often create walls that can freeze you in place, making it best to keep away from them.
3) (Optional) Capture the Malignant Heart
Upon being killed, Myraleth will drop a Malignant Heart that you can interact with to summon the Malignant Bloodlord once more.
Defeating Myraleth once more will cause it to drop a Caged Heart, which you can collect and later slot into certain Jewelry.
The Fissure of Malice has different types of enemies that range from the Iron Clan, Bloodletters, and even undead monsters. (This includes Myraleth)
It is easy to locate the 2 Malignant Ghouls as this Malignant Tunnel is not very big and you can see their locations once you are within a certain range.
Bringing a Devious Malignant Invoker will allow you to interact with the Devious Outgrowth that can be found within the Fissure of Malice.