Okay, this took me a while. I've managed to compile a list of every character in the MK universe:
Ankha
Appep
Art Lean
Asgaarth
Ashrah
Bannak
Baraka
Baron Reyland
Blaze
Bo' Rai Cho
Cassar
Chameleon
Chan
Cyrax
Dairou
Damashi
Darrius
Dion
DJ
Drahmin
Ermac
Frost
Fujin
Geneviere Reyland
Gorbak
Goro
Hannah
Hanzo Hasashi
Havik
Hinoka
Hornbuckle
Hotaru
Hsu Hao
Hydro
Jade
Jagatai
Jarek
Jataaka
Jax Briggs
Jerrod
Johnny Cage
Jola
Jonas
Kabal
Kai
Kali
Kano
Kebral
Kenshi
Keva
Khameleon
Kia
Kintaro
Kira
Kiri
Kitana
Kobra
Kreeya
Kumari
Kung Lao I
Kung Lao II
Li Mei
Liu Kang
Lucifer
Master Cho
Mavado
Meat
Mika
Mileena
Mokap
Moloch
Monster
Motaro
Myst
Nightwolf
Nimbus Terrafeaux
Nitara
No Face
No Neck
Noob Saibot
Ohona
Omegis
Onaga
Orochi
Peron
Qali
Quan Chi
Quin
Raiden
Rain
Reiko
Reptile
Ruby
Sareena
Scorpion
Sektor
Shang Tsung
Shao Kahn
Sheeva
Shinnok
Shujinko
Siann
Sindel
Siro
Skeleton
Smoke
Sonya Blade
Sora
Stryker
Sub-Zero IV
Sub-Zero V
Sub-Zero VI
Taja
Takeda
Tanya
Tassia
Tomas
Torch
Tremor
Vorpax
Warlord
Xian
Zeffeero
Tell me if i forgot anyone, or if you dont know who someone is on the list
Ankha
Appep
Art Lean
Asgaarth
Ashrah
Bannak
Baraka
Baron Reyland
Blaze
Bo' Rai Cho
Cassar
Chameleon
Chan
Cyrax
Dairou
Damashi
Darrius
Dion
DJ
Drahmin
Ermac
Frost
Fujin
Geneviere Reyland
Gorbak
Goro
Hannah
Hanzo Hasashi
Havik
Hinoka
Hornbuckle
Hotaru
Hsu Hao
Hydro
Jade
Jagatai
Jarek
Jataaka
Jax Briggs
Jerrod
Johnny Cage
Jola
Jonas
Kabal
Kai
Kali
Kano
Kebral
Kenshi
Keva
Khameleon
Kia
Kintaro
Kira
Kiri
Kitana
Kobra
Kreeya
Kumari
Kung Lao I
Kung Lao II
Li Mei
Liu Kang
Lucifer
Master Cho
Mavado
Meat
Mika
Mileena
Mokap
Moloch
Monster
Motaro
Myst
Nightwolf
Nimbus Terrafeaux
Nitara
No Face
No Neck
Noob Saibot
Ohona
Omegis
Onaga
Orochi
Peron
Qali
Quan Chi
Quin
Raiden
Rain
Reiko
Reptile
Ruby
Sareena
Scorpion
Sektor
Shang Tsung
Shao Kahn
Sheeva
Shinnok
Shujinko
Siann
Sindel
Siro
Skeleton
Smoke
Sonya Blade
Sora
Stryker
Sub-Zero IV
Sub-Zero V
Sub-Zero VI
Taja
Takeda
Tanya
Tassia
Tomas
Torch
Tremor
Vorpax
Warlord
Xian
Zeffeero
Tell me if i forgot anyone, or if you dont know who someone is on the list