Nothing is known about Mitchell before joining Department K, and its covert Canadian super-human group known as Weapon P.R.I.M.E. As a recruit of the new team with field leaders Weapon X and Yeti, Mitchell took up the code-name Tigerstryke.
Despite not being ready, Tigerstryke and the team were joined by Rictor, Grizzly, and led by S.H.I.E.L.D. agent Bridge in an off-the-books joint effort to apprehend Cable. Tigerstryke and the team attacked X-Force headquarters in the Adirondack Mountains, but due to zero prep time and being outnumbered the team lost. Tigerstryke chose to go head-to-head with Siryn and took a full-on sonic scream liquifying the circuits in his suit. Defeated, an explosion went off thanks secretly to Tolliver, but before they could escape they were all caught in the second explosion. Despite this, and being a walking body cast thanks to Siryn, Tigerstryke, Yeti, and Grizzly managed to not only survive but escape the rubble leaving the others with X-Force.
When Bridge's removal and S.H.I.E.L.D. and Kane were no longer with them, Tigerstryke was appointed new team leader.
Tigerstryke would first see action as team leader when Domino and ex-teammate Grizzly, posing as Val Cooper and head of Department K's General Clarke, broke into the department's bunker to steal classified files. Being sent to stop the infiltrators Tigerstryke saw his ex-teammate Grizzly, and even if Grizzly was briefly under his command Tigerstryke didn't hesitate in giving the order to attack. He and the others tried to keep the intruders busy so Killspree can get the drop on them but failed thanks to Hammer, who was keeping an eye on them while secretly downloading the files they came for. When Grizzly blasted a hole in the sewer runoff access duct above them, Tigerstryke ordered the twins Double Trouble to use a Strafing Fire maneuver to stop their escape.
But Grizzly and Domino managed to make it through the sewer, and get outside of Department K's Complex. As they escaped Tigerstryke with the twins behind him gave chase, Tigerstryke nearly caught up to Hammer's RV when it turned into a jet allowing them to get away.
When the group was dispatched to capture Northstar, Mitchell led the team in a chase for him around the globe. He finally gave up in New Orleans after realizing that there was no reason to capture Northstar, especially since he had helped P.R.I.M.E. in Russia.
