The post trilogy characters really weren't shown in the best light during their debut days. Some of their designs were... meh, a lot of the characters gameplay were generic and boring and some characters stories were so miniscule. What was bad was that these characters were very much underdeveloped, they had little time to grow which of course made many people think they were automatically bad characters.
These are just some brief ideas of the play styles/gameplay potential for some of the post trilogy era characters that I had in mind
Sareena - They could give her the demon stuff that they gave Kenshi since it really doesn't fit him to begin with, transform her into her demon form for the variation since the gave Leatherface different costumes per variation and boom....cool character.
Fujin - Tornado debris, wind guts, aerial combat, his crossbow from MK4 etc.
Frost - Nimble, ice weaponry, ice projectiles, raining icicles ect. This could work. Hell there are some moves that Sub-Zero had in MKvsDC that he never had in any other game they could give her.(some people might not be too fond of this idea though)
Li Mei - She should be the female Liu Kang of the game. Give her something more than just power blasts and spin kicks. Make her a real martial artist since she was trained to be one anyway. She should be the fastest and most nimble female character in the game; i.e. female Liu Kang for the average gameplayer. Someone you can pick up and easily play without much thought or effort. A perfect entry character.
Nitara - They could give her some stuff like glamour stun, some aerial flight moves and more moves centered around blood and biting.
Havik - Have him use his limbs as weaponry and then reattach. Make him just nuts to watch and play as. The games are already rated M, go ballistic with the gore and the appeal will be there.
Kira - Being a female Black Dragon member, she had an interesting concept. The problem was that they just that they just made her a mix of Kano and Sonya. Considering her bio, she could have all kinds of guns/artillery. She could have special gadgets/bombs/futuristic tech. An AK-47 with a blade attached to it. Land mines, dynamite etc.
