So, there is a mod for adding Doppleganger Style:
http://s1.zetaboards.com/InfernalWorks/topic/5430997/1/
They could bring it back and maybe re-implement that coop mechanic from DMC3 but improved, maybe with split screen where half of the screen follows the Doppler and the other half follows Dante. Also, you could press the Style button once to summon the Doppler and then use the Style button and with directions to perform specific Doppleganger moves, to do in tandem with the Doppler.
http://s1.zetaboards.com/InfernalWorks/topic/5430997/1/
They could bring it back and maybe re-implement that coop mechanic from DMC3 but improved, maybe with split screen where half of the screen follows the Doppler and the other half follows Dante. Also, you could press the Style button once to summon the Doppler and then use the Style button and with directions to perform specific Doppleganger moves, to do in tandem with the Doppler.