Complete Mass Effect 2 twice, or complete it once with a character imported from Mass Effect 1

Use the Omega 4 Relay

Hack a geth collective

Gain the loyalty of the Cerberus Operative

Gain the loyalty of the Cerberus Officer

Gain the loyalty of the Assassin

Obtain geth technology

Gain the loyalty of the Professor

Thresher Maw defeated

Successfully recruit the Assassin

Successfully recruit the Quarian

Successfully recruit the biotic Convict