Also, I forgot to mention Kate Blanchett's character.
She had the ability to be AWESOME but she ended up just being lame. The only times she actually did anything was the fencing scene which was another one of those too over the top scenes and when she failed to use her ability twice.
But before that, lets look at some of the other Indy villains. Raiders had the German guy who burned his hand and used that to build the staff. Temple of Doom had the guy who ripped someone's heart out and showed it to him. Last Crusade had the evil bastard who shot Sean Connery. Really, who shoots Sean Connery?
What did the chick in the Crystal Skull have? A psychic ability that didn't work and a sword. Whoop-dee-freaking do.
If they actually wanted to make her cool, they wouldn't show her failing miserably twice at her talent but instead had her do something like actually controlling the triple agent. He could have actually been a CIA agent but then she could be controlling him and that would make her cool. It might even make the crystal skulls make sense.