Yes, it is one of our jobs as parents to do what we can to protect our children from anyone who intends them harm.
But, "I will do whatever I can to keep you safe" and "I will brutalize anyone who hurts you" are not the same thing.
The first sentence is protective. The second sentence is violent.
I have worked with countless survivors of sexual abuse and domestic violence who never shared their traumatic experiences with parent figures out of fear that their parents would tear their perpetrators limb by limb, which would only add to their trauma of witnessing violence, and potentially lead to their caregivers ending up on jail and not do anything to actually protect them or help them heal from the pain.
You can tell your kids, "I will always be here to get you out of harms way, and I will believe you, and be a refuge and a barrier between you and whoever has abused you".
This is protective and comforting to your kids, without being scary. We don't need to threaten to become their perpetrator's perpetrator in order to convey our dedication to their protection.