scorpion and subzeros souls become intertwined resulting in a schizophreniclike ninja with power over both fire and ice. due to the volatile nature of these two sworn enemies being thrust together as one being his mind is fractured and paranoid having two different personalities each one believing the other to be chasing him (and also unaware that it is in fact himself). one is violent and afraid, almost maniacal, the other is more brooding.
either way he has control of both fire and ice. his weapons would be a chain similar to scorpion except its a claw rather then a dagger at the end. and instead of pulling the target to him, he pulls the target in the air as the same time he jumps in the air for a midair collision. he can also summon a sword like sub zero except it is in fact two swords, made out of ice and on fire at the same time, obviously this means they melt relatively quickly so instead of breaking them like subby does his sword, they melt.
his fatality could involve him summon one of those swords but its just ice (no fire) then he impales the person with it, then he summons the fire in a blast form which rips thru the impaled section, leaving a smoldering bubbly hole where he impaled the enemy.
for specials give him at least one freeze move that has the option to instead of just using it to generate a combo, also has the option to snap his fingers (while the enemy is frozen) and the frozen target gets set on fire. he should have a teleport punch, but instead of scorpions, make him appear beneath the target for a uppercut, a powered up (one bar) version could be used to start a combo maybe (makes it a juggle).
he should wander outworld and maybe earthrealm aimlessly trying to figure out who he is and whats chasing him, allying himself with however he believes could help him discover these things.