Board Thread:Spoilers!/@comment-27060727-20160225003107/@comment-26830263-20160320005725

Maybe ep 16 is for Zelena in present day and Hades in flashback already (though I find it strange that there isn't any news of them casting Zeus), and Last Rites is a Robin Hood episode, in which he'll die.

Another option is that Last Rites is still a Hades episode and Prince Marcus is Zeus, his description sounds really fit