Just using blanket kick will render most casters useless and they'll eat at least half of that killing spree.
On topic: Unpopular opinion but since you took pve gear into account eclipsed Starfires are spammable and can 3-4 shot most classes.
Soul fire is better with demo lock cause when targets are at or lower than 35% hp the cast time is lowered by a lot. (Not sure about the exact percentage as I haven't played a lock in years)