not the best picture....

Prof.mashi darcues: he is a Japanese immigrant who learnt English in England (so he talks in a British accent) he is also a very famous scientist who was always covered in paparazzi, secretly he started a project on mutation, his brother, pardon the armadilo, volunteered to be showered with mutation to discover it's abilities. But as mashi brought the tube of mutation into place his slipped some of it dripping out, the capsule went flying in the air and it all fell on mashi....and it gave him shapeshifting abilities however...with such power mashi felt superior, he locked all the witnesses in a wardrobe (there weren't many) so mashi plotted to take over the world...

However he ran into scave holding eggman's dead body (see sonic collision) mashi offered to save him for the alliance of the eggman empire, scave took the offer and they worked together for a bit until mashi betrayed them taking some of their robots. Mashi merged with the end as a last resort, sonic beat him and he reverted back to normal thus mashi became one of sonic's powerful enemies.

Relationships:

Eggman: mashi and eggman worked together in college however they got into fights alot and eggman dropped out. Later mashi saved eggman's life but betrayed him after eggman helped him make multiple robots.

Marina: mashi met marina at age 14 when he worked in an arcade (tipper's to be Precise) and he and she fell in love. After sonic beat him mashi went on to marry marina.

Sonic and crew: when mashi met them he was evil but he made sure no one knew of his plot. Sonic saved mashi from a huge paparazzi mashi acted as if he where sonic's friend however he betrayed sonic and later eggman andnow they are enemies always at battle.

Scave: mashi and scave are equally violent but mashi does it in Secrecy scave hated mashi after he betrayed eggman and scave topically attempts to kill him.

Powers and abilities:

Mashi can shapshift into anyone and can use their abilities. He also has robotics skills creating the nigiri army but he is better at genetic science.

Aftermath:

Every now and then the darcues family goes to tipper's where marina and mashi met. their kids (now teenagers) play the games mashi turns back on. The darcues family is just a happy family ...but evil. But happy.

(note; once again this is a copy and paste of a post on sonic wiki zone.)