Play as Minion Of Chaos:
At the character selection screen, press L1 + L2 + R1 + R2 + Up + X.

Play as Minion Of Order:
At the character selection screen, press Left + Square, Right + Circle.

Play as Lord Of Chaos:
At the character selection screen, press the D-pad in a Half-Circle counter-clockwise direction starting from Up, then press Triangle + X .

Play as Strahd:
At the character selection screen, press the D-pad in a Full-Circle counter-clockwise direction starting from Up, then press R1, R2, L2, L1.