New secret character Cosmo Pavone.

Go to Cappella Magna. Choose character that hasn't benefited from any Golden Eggs. Next get the Ebony Wings and Peachone weapons while playing. After passing the Crown and Tiragisu stage items the player will find a gated-off balcony with a Nduja Fritta Tanto in front. Now walk down the balcony and pick-up Cosmo.
Everything is on video.