When he drops grenades on the floor, go throw those back at him. You need to be facing him while in front of the grenade. When he turns facing you and starts canalizing a spell, move so you’re on his side or back.
Use totems to CC 2 elementals before the fight. If you have big red eyes on you run away from elementals. When they become very shiny they take 150% more damage but they also hit harder, so kill them with range. Don’t stand near the boss.
She will throw azerite on the ground. You want to be standing in between the boss and the azerite. She will then push you away, avoid it by going sideways. (thanks to u/Antisceptic)
If big north korean missile is running to you, go away from your friends. If you have a big red arrow on your head, go near a big rocket.