You can switch between John and Charlotte at any time - John's obviously the whip-crackin' tank, while Charlotte's spell books can spit out some major damage from far away. The longer you hold down the attack button, the more powerful her attack becomes. To keep her safe, you can send John ahead to act as a human shield, giving her enough time to sling her powered-up attack.
If you're one of the many fans who's complained that the towering bosses of Dracula's castle have been getting progressively easier over the years, know that the oozing, gory creatures in Portrait will stretch your skills further than before. They're designed so that you have to constantly dance back and forth as John and Charlotte, using their unique moves and co-op attacks to bring the baddie down. We can't wait to see how it all plays in the two-player co-op mode, but from the look of it, this mode won't be the complete game... just a selection of special areas.
Before you go, hit up the Movies tab for the latest trailer, showcasing everything we've mentioned, from the dual attacks to the hulking bosses to those two vamped-out sisters. Oh yes.