Ashura in Sonic 1 is a ROM hack of the classic Sega Genesis game Sonic the Hedgehog. ROM hacks are fan-made modifications to original games, and this one likely involves replacing Sonic's character model and potentially gameplay elements with the character 'Ashura.'  It's important to note that this isn't an officially released title; rather, it’s a community-created modification of the original game, made by independent developers within the Sonic fan community. Further details on the exact changes or the creator(s) would require searching within dedicated ROM hacking communities. 

Ashura in Sonic 1

Art Alive (World)