Lets start with the basics Nightmare has 3 different standard attacks Range Mage Melee Grasping Claws: During all of her phases she will also use Grasping Claws, which spawns small black holes around the room, try to avoid these. Phase 1: Husks: 2 husks spawn around you, and you cannot move until they are killed. Flower Power: The room will be split into four sections, one quadrant of the room will be safe(white flowers) Phase transitions: When you deplete the Nightmares health bar, she will heal up and become immune until you kill all the four towers, in this time she can still attack. When you have killed all the four towers, she will teleport to the middle and a Sleepwalker will spawn(always in the north corner). If you fail to kill this before it reaches the middle, you will be oneshot by her next abilty. Phase 2: Curse: In this phase, you have to deal with curse which will swap your prayers around. Pray melee will now be magic, and pray mage will now be pray range. Parasite: You will also be impregnated with a parasite, I recommend being at high health when this explodes as it can hit up to 60+ damage. You need to kill this ASAP. Otherwise it will heal the boss massive amounts. Phase 3: Spores: In this phase you have to avoid the spores she will spawn around the room, you need to have 1 tiles between you and the spore. If you are hit, your attack and movement speed will be reduced greatly. If you cant avoid them, going to a tower or something then just get hit by it. Surge: the Nightmare will sometimes teleport to one of the four edges in the room and surge across to the opposite side. This can hit up to 60 damage and she can also cast her other abilities during the surge and combo you for over 100 damage if you are unlucky. Keep an eye on this and don't get hit, Now that we have covered all the abilities, it is time to explain how to kill this boss. Something I noticed while trying out this boss, is that her mage attack is significantly faster than her range attack. So what I do is that I keep up Soul Split to heal a lot of the damage that I take, and whenever I see her moving to do an attack I always switch to mage pray first, and then switch to range. Her melee attack is just as fast as her mage attack, but less accurate so I just let it go through. Check out my video to get a better understanding of how the fight works. Now lets take a look at the gear and inventory I bring for this fight For your gear, you want to have high damage dealing gear, while still being tanky. Torva works very well with this, especially with the extra health you can heal to(up to 149 with full set!) This is the set I currently use And this is my inventory Dragon Warhammer is very useful to lower her defences and will increase your accuracy greatly. For every new phase, her defences will recover to normal and you will need to dwh spec again.