"I AM GOD!"
X, or better known as Sonic.exe (sometimes spelled as Sonic.EXE), is the titular main antagonist of the Creepypasta of the same name and its sequel "Sonic.exe/Round 2", and is the overall main antagonist of the series.
Sonic.exe is an interdimensional energy-based entity that possesses a CD-ROM of the original Sonic the Hedgehog, taking on the form of the titular main character. Then, he proceeds to "kill" the in-game characters before attacking and removing the soul/killing the person playing his game.
Portraits of Sonic.exe can be seen inside Enoch's Castle.
"Hello... Are you ready to play?"
Sonic.exe appears as the main antagonist in the level. For the majority of the level, he was never seen despite being recruited by Grand Emperor Enoch. At the Bloodbaths, Sonic.exe finally appears and meets Sonic, Tails, and Knuckles and asks them if they want to play with him. The three agree and sends the three into different areas - Sonic at a race track, Tails at a large vat of blood at the Bloodbaths, and Knuckles at Flame Core from Sonic '06.