Abyss power quest is unfulfillable for me

Hello,

I have a small problem. I died while fighting the boss in the Abyss biome, on the path leading to the "Abyss Power" quest, which is the only way forward. However, the biome has since changed into a desert, and I'm no longer able to complete the map objective, which requires me to kill the Abyss boss on the map. The problem is that the boss is simply no longer there.

I'm not sure what to do, and I can't continue progressing any further.

Fixed