Shane was a Changeling, one of the hundred sent out by the Great Link, found and raised by Klingons. (Star Trek: Phoenix-X)

History

In 2358, Shane was found and lived aboard the IKS Hou-Ling for many years under Captain Sergio's protection. ("Lost Aquarius")

While there, Shane was forced to negotiate with the Borg Queen when a Borg cube attempted to assimilate the crew. He offered her half his Changeling protoplasm in order to let them go. The queen accepted, and thus Shane gave birth to his 'other half', or twin, Shoon. ("The Return of the Borg")

In 2375, Captain Tweed of the Hannibal captured and contained Shane during a conflict with the Hou-Ling before the Hou-Ling was destoyed under transwarp pressures in a Carthaginian shield. Unable to deal with Shane, Tweed gave him to Captain Daniel of the USS Phoenix-X, who protected Shane when Shane didn't want to go back to living as a child under Sergio. When it was revealed Sergio was a Changeling to be returned to the Traveling Link himself, Daniel agreed to allow Shane to live and work aboard the Phoenix-X. ("Lost Aquarius")

In 2376, Shane sacrificed himself for the crew of the Phoenix-X when a cube attempted to assimilate them. This time, Shane offered his whole self to the Borg Collective, who, by this time, had experimented with assimilating changeling protoplasm, using Shoon. It wasn't long before the Borg assimilated Shane. In order to diffuse the assimilating nano-probes, Daniel linked himself with Shane and took on half the probes. The nano-probe density became so low in both Shane and Daniel that the Borg had no longer any control over them. ("The Return of the Borg")

A few months later, Shane was abducted by a Doctor Steve, along with Captain Daniel, who ran changeling experiments on them. Two months later, the two were rescued by Commander Gotens. ("Experimentalism")

In 2378, Shane was abducted by the Borg once again, who successfully re-assimilated him into the collective. They ordered Shane to capture an omni'X, which they would use to empower the collective with omnipotent capabilities. Unfortunately, the power only went as far as a single Borg cube. In order to diffuse the nano-probes, Daniel linked himself with Shane once more; except this time, the link knocked both of them unconscious. The Traveling Link then took on Shane's liquid and added it to their link, and vowed to track down the omni'Cube and stop them for as long as it would take. ("Destiny's Revenge, Part III")