Darkspine Sonic is one of Sonic's super transformations, appearing in Sonic and the Secret Rings. Rather than Chaos Emeralds, he uses the power of the World Rings. He is playable in the final battle against Alf-Layla-wa-Layla, an enhanced form of Erazor Djinn.
In this form, Sonic has increased strength and the ability to fly, along with his ring powers Time Break and Speed Break. His attacks are also more close-combat based, as opposed to the boosting and energy moves that Super Sonic uses. He does not lose rings gradually like Super Sonic, but he can lose rings from being hit.
His fur becomes pink\purple in color with two golden rings around his wrists and two around his ankles. His gloves and shoes disappear, too. Two white lines come down from the middle of his forehead and white markings outline where the straps of his shoes were. His skin turns pale white, and his irises and pupils disappear. Also, his voice has a slight change, becoming more demonic, but maintaining Sonic's pitch, possibly due to the negative ring energies that give a slightly evil side effect.
- This form seems to resemble Dark Super Sonic from Sonic X. Both are darker, more sinister forms provoked by negative emotions.
- Sonic's body and clothing merges in on itself when he becomes Darkspine Sonic, which is why his feet resemble his shoes, his arms appear the same colour as his body, the cuffs on his shoes and gloves become Rings and why his eyes appear as they are.
- Darkspine Sonic has Shahra the Ring Genie's gem imbedded in his right palm.
- Darkspine Sonic is one of three forced Sonic transformations, the others being Sonic the Werehog and Excalibur Sonic.
- Darkspine Sonic can be considered the first incomplete Super Transformation, as only three of the seven rings were absorbed, where as other forms have taken the power of a complete set of items. There may be a higher form of Darkspine Sonic due to the fact he did not absorb all the World Rings. However, it is unlikely that Darkspine Sonic, or any variation, will return in future games.
- It is possible that the fiery aura around Darkspine Sonic is the reaction of the 'judgement' flame to the three World Rings that Sonic absorbed.
- Darkspine Sonic sounds Like Sonic The Werehog if you listen closely, like when he Says "Shahra!" after you hear Shahra's spirit talk during the final battle.