Blue-Eyes Black Hydra

[The Seventh Samurai]

 

I'm not sure exactly what number to use for the damage multiplier here.  Do keep in mind that it's intended for use in a deck that has one card who's name is treated as "Blue-Eyes White Dragon" while on the field or in the grave and one card that does the same thing with Red-Eyes, so you could potentially have a total of 12 blue-eyes and red-eyes named cards in your grave.  I made it's effect resolve in the standby phase instead of the end phase just so we don't see a late game dragon's mirror causing 4000 damage without giving the opponent a full chance to do something about it.