You face Grievous and two Magnaguards in a warehouse 50m apart but you get some help.
You receive the Bat suit and all its equipment and are trained by Batman (from the Dark Knight) for three month. You also have the Iron Man repulsors but they have to recharge for 2 minutes every time you use them.
Finally, you can use this link and if you get a character they will help you and if you get an item then you may use it.
Good luck and comment below if you defeated him