Cannibal Fire-Eaters have the highest chance to spawn in Shore, but it is not 100%. You can also try other maps, such as Beach or Peninsula. Clear the area of any monsters so you don’t get killed while summoning. Unequip your Trigger wand if you have one. Take the desecrate gem out of the wand. Link it with spell echo to desecrate more corpses in one go. Hold ‘a’ to target the Fire-Eater corpse, and cast Raise Spectre.
We only need 1 Return to your Hideout. You want to go to the highest level area available to get high level spectres. I will go to my mine for monster level 83. Other places you can use are: highest available map, Shaper portal from global 820, Oba’s Cursed Trove (last room = i84), etc. Remove and re-equip your ‘raise spectre’ gem to despawn the low-level spectres Create new corpses with desecrate. They will be level 83. Hold ‘a’ on your keyboard to highlight Cannibal Fire-Eater corpse. Raise new spectres. Repeat until you have 4 spectres.
Don’t forget to put all your gems back into their correct places!.