I've had my rog 2 about 1 month and a half. I have the phone charged at 90% and over night its completely depleted. Is this a defect or am I doing something wrong?
It should not depleted overnight. I suggest you to do factory reset and if that doesnt fix the problem then take it to service center
Like @Akash Gupta said. Do a full factory reset and charge the phone before leaving it overnight. If you're still experiencing the issue you should take the device to your local ASUS support.