Corse are BLM type monsters. They will cast various Black magic spells including -ga spells and Ancient Magic. If boosted by Memento Mori the damage can impress.

Danse Macabre is quite dangerous if a strong helper gets charmed. It does not work on a Beastmaster's pet.

Silence Seal is a problem for casters and ninja.

Corse only spawn at night, between the hours of 20:00 and 4:00

This spell can be soloed by a 72+ Blue mage with great risk. Help is recommended. A high level Beastmaster is perfect for getting the spell. If you choose to try with a regular party, it should be balanced and weighted toward 70+ members.

There is aggro on the way to, and near, camp. Sneak and Invisibility should be at hand. Echo Drops to deal with silence, and Antidotes for the nasty poison from local plants will help. Setting Head Butt, Chaotic Eye, and several sleep spells is important.

Proceed to Attohwa Chasm and move to camp in the F-8 area, the marked camp above is a safe spot, as is the SE corner of the F-8 square. Note that there are sound aggro Hecteyes in the tunnels, and sound aggro Scorpions and Antlions, and sight aggro Goblins on the way to camp. Take proper precautions.

Once you reach the left side of the chasm, getting to camp is annoying. There are walls of Black Mist that prevent your walking through many of the paths. Use the maze method to find your way, follow the wall on your left until you pop out into the open area near camp. It will take a bit of time to wind your way to it.

There are plants along the way to camp that produce a green gas that will poison you if you get near them. Use a spell or Antidote to cure it. Keep sneak up at all times, as Pit Antlions can aggro sound as you cross cracks in the ground. They can spring up from below and attack if you are not sneaked. Once in camp, there are several Scorpions in the area, they can aggro, so be aware of them.

Several Corse will spawn in the red circled area when night (20:00-04:00) falls. Other Undead pop near also. So be ready for them. They will aggro low HP, so they can complicate a fight.

If a Beastmaster is helping you, they can easily solo the Corse with no direct help, using the local Scorpions and Flys. Silencing the Corse will help the Beastmaster's pet last longer. Other then that, it's best to hang back, and let the pet do all the work. Since It cannot be charmed by Danse Macabre, there is little risk.

If you are with a party, then stunning ga spells is an important part of the Blue Mages job. Also, if the Corse charms one of the party, sleeping that person as soon as possible is important. Dance Macabre targets the person with the most hate, and does not last too long, so a sleep is enough to wait out it's duration. Monks are very useful for these fights as H2H does extra damage on bones.

Avoid the Arch Corse. They are very difficult to kill, and highly dangerous. More importantly, as you have a limited time each night when the Corse will pop, wasting time on any one kill might lead to a long wait for the next evening if you fail to learn the spell.

Memento Mori can be learned on the proper Limbus run. You must be on or past CoP 8-2 to enter Limbus, and have gotten the proper Limbus key items for entry to this area. Your Limbus party should be more then able to deal with this Corse.

Memento Mori can be learned in the uncapped Totentanz ENM in Boneyard Gully, located in the northern part of the chasm. Take care when getting to the gully for the fight, as there are many aggro mobs on the way.