The included ragdoll control is an example of how to lerp strength on and off. You can make the whole ragdoll weak or just the limbs you want, for example an arm, a leg or the head. You can make the ragdoll follow the animation weakly so that it tries to follow the animation but at the same time is affected by physics. This asset makes it easy to have partial ragdoll effects. You don't even need a death animation to make it ragdoll like in the video, but if you want to add some flare to your death so that it is not just a canned death animation nor just the standard ragdoll death you can make any mixture of the two.
I am happy you find this cool and amusing.