If you’re using Stadia this may be pretty rad, however, Android Authority is reporting that it may interfere with your WiFi reception
Because of the way the controller hugs and covers the top and bottom edges of the phone, it can have a detrimental effect on some Wi-Fi connections. This was the case for the Pixel 3 and OnePlus 7 that I used for testing, and I suspect it will hold true for other phones as well. Switching from any other standard controller to the Razer Kishi resulted in immediate stuttering in video and audio while streaming games, even with no change in environment.Source
Razer announces the immediate availability of the Razer Kishi Universal Gaming Controller for Android™, a new mobile accessory which took home two Best of CES awards this January. An iPhone version is slated to arrive later this summer.
The Razer Kishi brings advanced gaming features to mobile players, with increased precision and expanded controls thanks to its clickable analog thumbsticks, arrays of face and multi-function buttons, and 8-way D-pad. It also comes with two analog triggers and two bumper buttons for a triple-A, console-level gameplay experience anywhere.
The Razer Kishi’s flexible design supports a wide range of Android™ smartphones and the direct USB-C connection virtually eliminates input lag, allowing users to enjoy ultra-low latency gameplay. Extended play times of Android™ games or cloud game streaming services are supported via pass-through smartphone charging.