So, a lot of people already knew this, but I play DN with a controller. PS4 habits. Anyhow, the standard PS4 controller has full support. Energy wheel using the touchpad, short commands also using the touchpad, analog support, face/dpad controls work, everything works exactly the same as it would on the PS4.
You'd think the Razer Raiju would have the same support. Well, it does. Mostly. The additional buttons can't be remapped (for whatever weird reason) the touchpad is unresponsive (aside from pressing it to bring up the energy wheel and short commands). The additional buttons actually do what the trigger buttons do. Which, is weird. I've already spoken to Razer, I'm still in the process of doing a full setup/support much like the standard PS4 controller has. It's gonna take a while.
Either there's not a true support yet, or it has to wait for Steam to let this happen.