Board Thread:Boruto Discussions/@comment-25122992-20170223182539/@comment-4080775-20170301192148

They could get worn down by other forces or greatly weakened by a technique before their deaths. Or killed via poisons or induced illnesses. There are plenty of ways to dispatch a strong character without nerfing them. Also, they could always be sealed away. Soul–Body Separation Technique is a great example of how one could kill a foe quite easily.