Sub-Zero, Scorpion and Noob Saibot have almost become the "trinity" when it comes to the ninjas of Mortal Kombat. Their stories have the potential to become so tightly wound that it could make for some great dramatic tension. Also, below them you have Frost and Smoke as souls being fought over. I am not a big fan of the Frost character, but if Noob Saibot resurrected her as a wraith, then I could see Sub-Zero taking responsibility for her lost soul, and wanting to Fatality her and put her to rest for good.
Smoke is a character that is growing on me over time. Unlike Reptile, who I felt lost a lot of his potential by being revealed as a mere worm, I think Smoke gains something by not living up to his potential. He's the under-achieving friend of Sub-Zero's, who instead of regaining his soul and helping his old ally, is a mindless elemental husk who serves the older brother of his old ally, and is doing his bidding. I'd only bring back Smoke as a one-off to give Sub-Zero someone to kill. The idea of Noob throwing all these people Sub-Zero has loved and trusted at him as obstacles...intrigues me. I'm just reading up on IGN's greatest comic villains of all-time, so I'm thinking of that sort of approach -- but Noob could really be a fucking pain in Sub-Zero's side by using Frost and Smoke, although I am not a huge fan of either.
Ermac is a character that I think should be put on hiatus for a little bit. I'd have him do something heroic in Armageddon, his physical form is destroyed, and it is assumed that the souls that comprised Ermac ascend to The Heavens. But basically, the warrior souls that formed him saw a higher purpose in serving as Ermac, so they look to re-form over time, and will themselves into a being of light. So basically, Ermac takes MK9 off and comes back for MKX.
Jade is another character I would give a break to. Have her disappear during Armageddon, which can add to Kitana's stress (Kitana should definitely be back -- one of the best developed characters the MK Team has ever had). Eventually she returns, with her own agenda. Perhaps she discovers that King Jerrod's bloodline usurped the Edenian throne from her family, or something like that. Kitana vs. Jade would be an interesting fight.
Mileena deserves closure, but I don't think I would bring her back. Awesome character, but I feel that she has served her immediate purpose. Perhaps she can kill Shao Kahn, and then she just wanders off to find her own purpose, leaving it open for her to return in future games? Or maybe she could even take her life after killing Shao Kahn, admitting to herself that she is just a clone, a monstrocity, and on borrowed life (she was resurrected, remember). It'd be a downer for her, but it'd be peace for the character.
I'd have Tanya's status in MK9 as "missing," adding to Kitana's stress as there is the possibility she could return at any time, but I'd have Jade confirm that she killed Tanya when she returns. I don't hate the Tanya character, but I just don't see the purpose for her. If she did return, I'd like to see her with some major development. For example -- a lot of people have said that they have wanted a female sorcerer in the games. It would be cool to get a new character providing this, but Tanya could return having dabbled in sorcery, granting her new powers. She could get a new "voodoo priestest" look, or something.
Rain got some weird development, but it was almost like they just wanted him to be something, but made him too important to the story. I'm on the fence about him. If he came back, I'd like him to be further remodelled. Perhaps a name change, and a ditching of the purple theme would be good moves?
Of the cybernetic ninjas, I like Sektor and Cyrax the best, but I think they are best used as fodder to put over some other characters who need a boost. For example: I think Sektor should be killed by Jax, and perhaps Cyrax could be killed by Sektor, and the death of Cyrax could be used as a guilt-trip on Sonya.
