During this Tyranical week in Nokund Offensive on the last boss my group experienced Static spear doing extreme amount of damage on M+20.
Logs says the Static spear double hitting target for 200k + 160k (+overkill) nature damage which instant kill any target even with 20% def CD. I believe that second spear hit should go to all players pushed inside the cirle and not to the initial target.
In order to kill the boss we had to use big def + sacrifice on each group member for them to survive.