Cione was a member of Marius Blackwood's platoon, and one of his close friends. He was the second-to-last one to die, and the one that impacted Blackwood the hardest.
Biography
Cione served alongside Marius Blackwood, Stoltzfus, Billy Tallman, Marciniak all through their days in the academy. They had been part of the same platoon, and had saved one another on more then one occasion. After their platoon broke up, they all agreed to meet every year in Shiloh in a bar called the Shed. Gradually, one by one, the platoon began to miss the yearly meetup, having died in combat.
Cione was the last to die before Blackwood. A Crucio siege tank miscalculated his firing arc and fired on Cione's company. Cione was obliterated to the point where there wasn't even a body.
Cione's death deeply impacted Blackwood. He would refuse to upgrade his Arclite siege tank to a curcio siege tank due to it being the weapon that had killed him. During operations, he would hear Cione's voice telling him to never lose momentum.
References
McAleese, Danny. "Momentum." (May 22, 2013). Blizzard Entertainment. StarCraft Lore: Momentum Accessed 2013-05-22