Pic I found on deviant art but not the yellow on it
Factor-X upgrade is the name given to 4 special parts on the plasma caster.Zel'no'di ventured into a temple to find them and when he did he put it to use.
Abilties:Charges the plasma casters attack and forms a ball of energy that has the strength of 4 rocket launchers.The plasma turns purple it's called phantom plasma.
Trivia:Odd enough Zel'no'di's plama caster's plasma was red but the normal Predator has blue,while Factor-X upgrade turns it purple like it's mix of both of there strength's