Darkspine Sonic, one of the strongest transformations of Sonic if not THE strongest he has ever used, thanks to the power of three World Rings, Darkspine manages to use the power of flame (although it has not been clarified if he can control it as Blaze), wind and darkness.

This transformation appears only once, during the final showdown with the very embodiment of Arabian Nights, Alf-Layla wa-Layla

The latter uses the power of all 7 World Rings becoming the dimension itself so much to rewrite and modify it, while Darkspine uses only the energy of 3 World Rings composed of sinister feelings, thus fuelling his anger towards Erazor.

Despite the disparity of power, Darkspine manages to overwhelm Alf Layla wa-Layla, probably because Sonic is more adapted to this kind of transformations than Erazor, his power is such to reject the Spirit Blast of the enemy composed by the corrupt words of Arabian Nights.

Darkspine Sonic has demonstrated a profound and brutal form of hand-to-hand combat, being capable of delivering powerful punches and kicks in rapid succession. He is also able to perform Time Break and Speed Break without the use of Shahra's magic.

After the defeat of Alf Layla wa-Layla, Darkspine was able to restore the reality of Arabian Nights to the way it was before Erazor's transformation by simply expelling the powers of the World Rings from his body.

This is practically the power and skills of Darkspine Sonic, with only 3 World Rings, probably with all 7 World Rings and with them all the emotions of the words of Arabian Nights could reach a "Zen" state, lacking in emotions but still all together.

A little trivia: Darkspine Sonic is completely naked;
Another little trivia: Darkspine Sonic has practically punched a deity, very similar case with Demi-Fiend from Shin Megami Tensei III.