This is Act II of Ashes of The Abyss After Phase 5 of ETO: Ashes To The Wind, Observer Gaster forcefully merged everyone that was fighting the human into a singular being. This being, now known as The Singularity, is now dead set on destroying the human, but is also desperately struggling to remain sane and contain its own power. (btw the thing in the middle of the head is Singularity's eye)
Cage of Abyss by MC-Hooray Ending Time Octet by MC-Hooray End and Beginning by MC-Hooray Ashes of The Abyss by me Ending Time Octet: Ashes To The Wind by me Merged Consciousness by me Original Project and Sans sprite by @Lead-Tuner Edited Sprite by me