Comics Characters Who Are Hard to Use
1) Mad Jim Jaspers from Captain Britain
I'm going to confess here. This character is one of my favorites. He's basically a lot like the Joker. Strange costume. Twisted sense of humor. Deranged smile. He would be exactly like the Joker if not for one thing: Mad Jim Jaspers is essentially God.
In his first appearance, he's just an oddly-dressed criminal from that old comic standby the parallel universe. But when Allan Moore took over the character, he turns out to be an insane god-like mutant who killed all the suerheroes in his universe. He's so crazy turns his entire universe into a Salvitore Dali painting for shits and giggles.
And what's worse is that the main character,our hero, Captain Britain fails to stop him twice. The first time Jasper's is taken out it's because an outside agency destroys his universe while he's in it. The second time, Jaspers (actually his Marvel universe counterpart. It's complicated.) is taken out by the story arcs other major villain, The Fury. The heroes are more or less powerless against him. (Captain Britain's role in his defeat is literally consists of serving as bait).
Unfortunately, the character took a downturn the moment Allan Moore stopped writing him. When Chris Claremont brought the character back it was for "Die By the Sword" a crossover between the Exiles and Excalibur. The problem is that Jaspers doesn't work very well as a recurring villain. In order for him to work in the mainstream Marvel Universe, you have to power him down to the point where the character's have a chance of beating him. And that misses the point of the character.
Any Jim Jasper's story where the heroes aren't simply destroyed in the blink of an eye should have them turned into various horrible things while Jasper's toys with them. He's the one villain they can't beat. He's the guy against whom the only possible recourse is hoping that someone much more powerful take him out for you. (And I'm talking Eternity level power here). This means that he should used sparingly and only for stories where you want to kill off a whole bunch of major characters. (And you can't outside of What If?. Because I'm talking characters like Wolverine and Spider-Man). Otherwise, he's just another dime -a-dozen villain and he's much to good a character for that.