Ancient Xi
I think its a bit reaching to say that if the clans find out that MC can semi-infinitely revive they will turn humans into test subjects in case they can revive too. Its much more likely they will believe he has a treasure and try to get it out of him - he is the sole odd case and the clans have been dealing with humans long before he got there. Also would the clans want to make multiple people enemies because they cannot be killed - they seem like just the type of people you dont want to target.