Eternal items are simply rare drops you can increase their drop rates directly by getting the eternalized set affix and indirectly by increasing your luck and item drops stats and mythics can be crafted here’s a list on how to craft them all 
Eternal items are simply rare drops you can increase their drop rates directly by getting the eternalized set affix and indirectly by increasing your luck and item drops stats and mythics can be crafted here’s a list on how to craft them all