While normally Harvesters are some of the easiest pricks to kill, the ones in the Chasm are different. They are placed against an object on the map in which their "Feast" is able to go through. I have to use my ultimate to destroy all the Feasts that go through, since it's an AoE DoT attack (Veil of Blades). There shouldn't be an enemy we absolutely HAVE to use our ultimate on due to something they can use to continuously survive without us being able to stop it. If it's going to spawn, make it avoid the world.
Argonians always and forever.