The new USB-PD protocol is the fastest form of charging, but requires both the charger and phone to support it. Anker only has one charger that supports it.
The next fastest solution, which is a lot more prevalent is Qualcomm Quick Charge, which is on most new phones with Qualcomm Snapdragon processors. You will also need a battery pack that supports the same version as your phone.
Quick Charge Device List | Qualcomm
Lastly, Anker chargers have something called PowerIQ which adjusts output voltage based on the device it identifies. Unlike the two options above which require the device and supply to communicate and adjust voltage and current based on what the device's charging circuit requests, this solution just outputs a constant amount of power based on what the battery pack thinks is best for your device.
As far as I can tell the Dark Energy Poseiden doesn't support any of these and just outputs 5v at 2.4A, but I'd confirm that with them directly and see if they have something coming out to keep up with modern devices.