Karl Ruprecht Kroenen is possibly the best of three antagonists from the film Hellboy. A Nazi assassin who was Rasputin's servant in WWII, Kroenen became infamous for having replaced most of his organs with clockwork in order to "perfect" himself and boost his reflexes to abnormal limits. Winding his mechanical heart would make him move faster and become a more deadly weapon of the Third Reich. Sporting two wrist blades and executing anyone who stood in his master's way one by one, Kroenen proves to be an impressive and mysterious presence up to his resurrection seventy years after his own demise.