I have recently been seeing this happen, and was wondering if it is a bug or a cheat. I have an upgraded Palpatine, and can't do anywhere near as much damage as some players are doing. Like not even close. I have also seen a Palaptine that is taking an extraordinary number of hits with almost no damage. Like he is surrounded by 10 players all shooting him point blank and they all die and he takes no damage. I'll try to get a vid or at least the name of the player next time I see this. Also on PS4.
Are you holding down both left click and right? I use Palpatine a lot and it usually takes me a second to fry any regular trooper to crisp. Even faster if I have chain lightning on. Though a Palpatine taking no damage sounds a bit broken.
