The articles for the two novels from which this character originates have not been created yet, so I will place his info here. (He was originally given his own article be an anon.) This info can also be found in the Star Trek (Bantam) article's history.
Omne is a character from the Bantam novels "The Price of the Phoenix" and "The Fate of the Phoenix."
Omne is a mysterious figure, strongly opposed to Kirk and Spock and the Federation they represent. He has developed technology to resurrect himself in case of death.
He kills Kirk, forcing Spock to ally with the Romulan Commander (from the episode "The Enterprise Incident") and they discover that Omne is used his technology to two create identical copies of Kirk (one dies, the other lives). Spock battles Omne and he dies.
A second Omne returns and boards the Enterprise. He is killed by Kirk with an Old West revolver, only to be resurrected back in his lab, where (in the second book) he sets out again to dominate both Kirks, and battle Spock and the Romulan Commander. This time, he has the knowledge and abilities of Spock.