Kingdom Of Chaos mode:
Beat the game with Allen and load your cleared saved game file to be able to select any of the ten kingdoms at the Story mode selection screen.
Nemo campaign:
To unlock the Nemo campaign, recruit Nemo in Kingdom Of Chaos mode.
Bonus commanders:
Unlock the following commanders by searching for them in the corresponding locations:
Dora Jean – Search Baura
Jackal – Search Grapton
Knightly – Search Dabikk
Teri – Search Bull Cave