What if the concept was that the Forbidden Five were ancient ninjas who had fallen?

I think it would be great if they were originally ninjas protecting Wyldness, but were corrupted by Thunderfang (or someone else?) and turned into villains bent on destroying the entire realm, and their saga could be extended. Since they're the evil counterparts of the ninjas, how about changing the elements to something reminiscent of the ninjas? Like plasma, crystal, sand, magnet, and steam. The target they're trying to liberate isn't Thunderfang, but their own legendary ninja. What do you...