Night Sister Magicks vs Dark Side of the Force Powers (see details)

Both cannon and both at peak which is:-

1. More powerful
2. More versatile
3. More effective

Dark side is better. I mean there is a reason if the light and the dark side are the two leading ideologies of the Force

This goes for both threads-
Higher end Nightsister magicks are more versatile. They can conjure weapons and the like from nothingness, raise beings from the dead, and even use exotic voodoo rituals that even high end Sith (like Dooku) are defenseless against.

its apples and oranges, but I mean every time a nightsister has come up against a traditional force user they've come up short so there's your answer