Both sides could use bigger rosters.  The only crime here is having a select number of characters when Mk and DC have so much more to offer.

MK

• Goro
• Motaro
• Smoke
• Cyrax
• Kung Lao
• Kabal
• Shinnok
• Nightwolf
• Noob Saibot

DC

• Bane
• Clayface
• Mr. Freeze
• Green Arrow
• Atomic Skull
• Doomsday
• Brainiac
• Mxyzptlk [Only if he's voiced by Gilbert Gottfried]