There is a great danger that is on the horizon. It will take the League to gather intel and find out what is going on. It will be dangerous, much like a 007 mission. Everyone will have key points and such to uncover, with aspects of Laura Croft and a mixture of X-Men thrown in just for fun?
Someone wants to rule the world as usual but this time they are falling on sorcery and legend like Hell Boy when the man was trying to bring the creatures from another dimension into Earth.
There are several ways you can go with it, but it's literally up to you and the players. I will have my character up though, I'm working on him. Trying to make sure he'd be acceptable.