I worked out how to make Defenders by accident.
You take a husk body, one that the Mysticals had claimed as their own, and feed it a paste of the beans of the Wacca bush, mixed with crushed Rongin beetles that had only eaten Glowstalks.
True, I’d hoped the mixture would reclaim the body from the Mysticals, but a husk body that moved and fought to defend the village, that was useful. Although sadly they weren’t able to distinguish friendly outsiders from non-friendly.
But then all the other tribes began to attack us for some reason, so that didn’t matter.