Twist is the ultimate god who had been asleep for 100 years and awoke after the death of nazo.
he observes sonic and his friends and decides to show himself as a shadow with a little more personality on him

he showed up in front of sonic and asked him for a fight to test him

Twist met sonic as i said in the recent picture and became his friends
not only is he his friend but he is also his second rival (after Shadow)

When Twist is having a lot of fun his fur turns normal green but when he's serious his fur turns a little dark green