I have two suggestions :
dicechess game : Chess with dice, a pretty popular cool game, I don't know if you can add.
And omegachess . It is quite popular, even Judith Polgar played it, you can find it on youtube. Only with the figure "fool" Is desirable.
Three new figures: the sorcerer, the champion and the jester.

The "sorcerer" figure is located on 4 corner squares. These are full-fledged game cells. He walks with an elongated knight 's stroke , as well as 1 square diagonally . It is like an elephant figure walking across fields of the same color.
The "Champion" figure is located on the outermost margins - a jumping figure walking or jumping both one and two squares in all directions except for a move one square diagonally.
And the figure of the "Fool" is generally cool. The jester walks around mimicking the opponent's figures. That is, it has the rights to move the opponent's piece that has just descended. For example, if the opponent has a knight, a king and a pawn that he went down with, the fool can go down either as a knight or as a king or as a pawn.