Here's where some people differ.
In fantasy/sci-fi/and spec, it is sometimes a good idea to use the MC's name with the hook to save people from world building classifications. For instance, to say: "Now a Guardian must ..." is vague and impersonal. But "Lonko must" is direct and to the point.
Again, I've found in many cases that for fantasy and spec, or anything that has tons of world building elements, names work better, but only for the MC.
Following the kidnapping of her baby brother, Lonko - a Guardian in training - deserts her training to find him and must rely on Neda - a failed Myrodiancer - to overcome the strange magic wielded by the southern raiders.
SO you'd have:
Lonko's baby brother was kidnapped, and to find him she must abandon her training.
I stopped there because that's really the only thing you have that's hook worthy.
We still need to know what's in Lonko's way. Not the "Who" kidnapped her brother but the "Why" along with it a solid piece of conflict which makes us care about the MC and her journey.