Would everyone agree that Mortal Kombat wouldn't be Mortal Kombat with the following classic characters: Sub-Zero, Scorpion, Rayden, Sonya, Liu Kang and Johnny Cage? To me, these are the most central characters of the entire series and IMO, the cast of characters should always be built around them. Here are my reasons for each one:

SUB-ZERO: One of he first characters to have a stun move allowing opponent to get in "free hits".

SCORPION: RAYDEN: As an Elder God, he's been one of the forseers of the entire MK universe and, to me, the BIGGEST character storywise due to his ability to traverse the different realms.

SONYA: The very first female fighter, then had her purpose greatly expanded in MK3 when the story of the Outerworld Investigation Agency was introduced.

JOHNNY CAGE: His role as a martial arts movie maker gives him reason enough to appear in every game.

LIU KANG: Liu Kang didn't seem to become very popular until MK2 when he added the Bicycle Kick, the Low Fireball, and the ability to throw his High Fireball in mid-air. I felt in MK2 he was ovepowering and made him a favorite of the MK universe forever!

The only character of the original 7 playable characters in MK1 I neglected to include are Kano and Liu Kang. Kano seems to be a "supporting cast" character to Sonya and Jax.

Even in a game as dark as Deception sounds, the centerpieces, as I call them, would make it feel like classic MK all voer again.

Space3999