You're seeking vengeance thru the devil's mysterious power.
Red & Black devils possess the mysterious dark power, the Black Devil can cast a spell on your enemies and make them fall into the hell and beyond; Worse yet, your enemies better watch out. The Red Devil is all about shedding some blood and causing pains to those who give you troubles. However, the Devil will only punish the bastards. If you use it in a malice act toward innocent people, be careful - the Devil will hunt you down.