There appears to be a logical problem with the two sentences that makes them incompatible no matter what wording is used in the second sentence.
If the vigorous life force transcends life and death, then it is not subject to life and death.
Therefore, regardless of what word you use to end the second sentence, the second sentence will invalidate the first sentence.
The only way around this logical impossibility is to rephrase and combine the two sentences:
With the exception of the transcendent vigorous life force, everything external is subject to life and death.
Now, it could be that the vigorous life force transcends life and death because it is not actually external—but internal. In that case, the second sentence doesn't actually contradict the first from a logical perspective. However, it leads to confusion because it sounds as if it does.
If this is the case, then rewording the second sentence is still necessary to avoid this confusion. In doing so, I will use the final word that I think should actually be used rather than that or both:
Everything external is subject to life and death. The vigorous life force, being internal, transcends these.
It's an assumption on my part that the vigorous life force is one of several things that are internal. If that is a false assumption, then that should be explicitly spelled out:
Everything external is subject to life and death. Only the vigorous life force (alone being internal) transcends these.