To unlock you must simply complete the story mode beating all eight opponents using Kan-Ra on any difficulty earning any objectives.
If you want progress towards :
He has three objectives, and all can be completed in one run.
1) Beat story mode. Simply win all eight fights.
2) Earn 1750xp in a fight. This is basically a freebie. Land some big combos, mix it up and finish with an ultra to easily get over this limit.
3) Ultra combo Aganos. Simply beat Aganos with an Ultra in the final fight. His ultra is
when Aganos's health is reading 'danger'.