Just a small nitpick, sorry. War of Revenge would be Kostosota. Vihan Sota is War of Wrath.
Anyway, Finns destroying Germany is nothing new.:p After all, during the 30-years war a big chunk of Gustav II Adolph´s cavalry were Finns (the Hakkapeliittas).
Cankiwi,
The correct way to spell that would be Pahansisuinen Sota. I suppose it could work as a name, but might Kostosota ("War of Revenge") be better, since it is easier to say and so would propably be used more. Also if Finns are going to war out of revenge, naming the conflict like that...