Replying...
Intro. After a mysterious black substance infects Sonic the Hedgehog, a hidden entity named Ping begins slowly bonding with him, leaving glowing purple markings and influencing his thoughts and emotions. Though Sonic tries to live normally with help from his friends, especially Shadow, the entity eventually seizes control of his body, committing destructive acts while Sonic remains trapped in his own mind. Time and reality become distorted for him, and when control briefly returns, Sonic realizes Ping has been manipulating events for a long time. Now separated from his friends and unsure what is real, Sonic must fight to reclaim himself before the entity fully takes over.

Sonic AU Ping.EXE

@Keish