Blaze - Complete all missions in Konquest mode for all fighters. After that, highlight Raiden at the character selection screen and hold Down and hit Start. Thats how you play as Blaze.

Mokap - Highlight Cyrax at the character selection screen and hold Down and hit Start. All the missions in konquest mode have to be finished by all fighters too btw.

Both Mokap and Blaze aren't in MKD playable.