Oh, God. I refuse to believe there is an anti-Force. No thanks. Flash already has the Negative Speed Force.
__________________ RealistRacism: "Sheevites, much like the Banites, were meant to increase in power with each member. From Lightsnake to Gideon to Azronger, this was supposed to be the case. However, knowledge must've been lost in some kind of Gravid-like incident, as Az turned out to be a mid-tier debater with a sub-par track record, sh!itting all over Tempest's legacy. Sad."
Y'know, most star wars fans and authors just pretend that that whole Waru thing never happened. It's one of the most embarrasing things in all of star wars.
If I were to retcon it, I would just say that Waru described his ability to do what he did as an "anti-force" just to explain it in simple words to the inhabitants of our dimension, but considering he fixes things by putting them inside of a fluid inside of himself, the "anti-force" is probably nothing like the force.
How powerful is it? I'm guessing it only has power because it's a thing from one dimension in another. If it was in its dimesion, where the laws of physics are in line with how it acts, it wouldn't have any special "power"
And no, normal Sith and Jedi can't learn it, I think that was the point from the start.