A slightly less cheaty and more legal way to dupe nether stars would be to use reliquilairy. It does consume 3 wither skulls and some other things to dupe a nether star. And yes, the 3 skulls would be similair to acually killing a wither.. Just.. Without the killing part and more craftng part. We use this on our server alot cause its legal, doesn;t kil people and dont ruins the landscape if it escapes.. And by escape i mean from a totally unprotected little cave in our mining age... Wait.. Why do i care about the mining age landscape again?