You can use your Vita as an extra DualShock.
If you haven’t dished out money for an additional controller yet and fancy some two player action on PS4 then you’ll be happy to hear that your trusty Vita doubles up as an additional DualShock. Set up remote play as usual with the Vita. This will automatically turn off any connected controller and allow the handheld to control the on screen action. When you want a friend to join in, have them press the PS button on the DualShock and log in as another user or guest and you’ll have co-op Lego Marvel on the go in no time.