Special 10-year anniversary issue featuring an all-star artist jam. The celebration of Sonic's 10th Anniversary in comics might also be the beginning of the end for the blue blur, his friends and their enemies as well. The action picks up from the previous issue; Shadow returned to help in the fight against the alien Xorda who want nothing more than the destruction of Mobius. After reasoning and bargaining fail, the denizens of the planet must band together for their very survival! In the end, a hero will fall and the future of Mobius will be changed forever.
Sonic Adventure 2.5: Omega
Rotor builds a device to communicate with the Xorda, but Sally uses it and the Xorda won't listen to reason. Dr. Robotnik constructs Giga-Bot Prime and only Sonic can power it with his speed. Maximillian Acorn demands that Dr. Robotnik must give him half of his territories in exchange for Sonic's services. Everyone on Mobius, even rivals are willing to work together. Sally joins Sonic to destroy the Xorda with the robot, but after the threat disappears, Dr. Robotnik locks Sonic's feet in so he can never escape. The Xorda launch their ultimate weapon, the Quantum Dial to destroy the world. Meanwhile, Knuckles takes the biggest risk of his life and returns back to Mobius alive, losing his chance to become one with the Chaos Force. Giga Bot prime is destroyed when it flies near the Quantum Dial, freeing Sally and Sonic. Nicole states that if Sonic runs in the opposite direction of the dial, he can destroy it but will implode on impact. Knuckles destroys all of the Quantum Dial's defenses when he returns to life, but can't help Sonic as he has lost his chaos powers. Sonic goes ahead with his plan and disappears as he destroys the Quantum Dial. Knothole residents and Chaotix attend Sonic's funeral not knowing that 849,000 light years away, Sonic has been transported and still breathing...
This is the comic series' fifth milestone.
This issue features a number of different artists for every two or three pages.