In the 31st century, the Inhumans are enslaved under Attilan. Composite is a rumored experiment by the unknown "man behind the curtain" on Earth's Moon among the Inhuman slaves. Composite has the abilities of all the original Inhuman Royal Family including Black Bolt, Medusa, Triton and Gorgon.
Composite was created by Loki's selective breeding program. Composite is completely loyal and carried out the gladiatorial events that selected the other Inhumans Loki needed to help him invade Asgard. Those selected were the most powerful - Phobia, Imprint, Stupor and Wormhole.
Composite helped invade Asgard and was banished by Odin along with the others after their defeat.
Composite has all the powers of Black Bolt, Medusa, Gorgon and Triton. Powers displayed by Composite include super strength, seismic stomps, prehensile hair, and enhanced durability. Composite's mask is specially designed by Loki to surpress Black Bolt's extremely destructive sonic scream, which Loki has the key to.