<p>There is no exact time when it comes to that question. The world messages from this world change are not precise like other world bosses (Morgaroth,Orshabaal, Ferumbras, Ghazbaran), (Morgaroth, Orshabaal, Ferumbras or Ghazbaran), the time stamps for Feroxa<span style="color:#34495e; font-family:Ubuntu, Helvetica, Arial, FreeSans, sans-serif"><span font-family:Ubuntu,Helvetica,Arial,FreeSans,sans-serif"><span style="font-size:15px"> works </span></span>just like you described in the end of your question. I would recommend you to enter Feroxa<span style="color:#34495e; font-family:Ubuntu,Helvetica,Arial,FreeSans,sans-serif; font-size:15px">'s antechamber before 25 minutes after the first message</span> so you can be on the safe side. Goodluck</p>