Head to the right and bend the bars out of the way with Magneto's magnetism, then rotate the giant door's magnetic lock to access the cell block.
Mysterio will run on sight of Magneto and will flee to the upper right cell. Swap to Mystique and transform into a guard. Head into the elevator in the left corner and rise to the upper floor. Smash the box immediately to the right of the elevator when you reach the top to disable the camera. Take the lift as Magneto and destroy the debris blocking the right cell where Mysterio is hiding. Bend open the door and deliver the first dose of pain to Mysterio.
Smash the TV inside the cell and make the switch out of the parts. This switch reveals a target panel on the plastic doors of the cell below that Mysterio has moved to. Drop down, hit the panel and the doors will open. Deliver the second dose of pain.
Twist the magnetic pressure valve in the cell after he is gone to get the parts for a switch upstairs on the left. Head up, make and activate the final switch to enter the cell and finish the argument.
Stan Lee - In a cell on the left inside the cell block. Use an electricity based character to charge the electrical panel and release Stan.
Character - Green Goblin (Ultimate): In the rear right corner of the ground level of the cell block is a claw switch. Activate it to open the cell door and nab the token.
Red Brick - On the right wall is a symbiote puddle for a symbiote character to use. Enter it to reach the office in the back, as well as the red brick.
True believer (35,000 studs): Collect the specified number of studs during the level to obtain a gold brick.