The descendants held prisoner by the Skettis talonpriests are listed in this book: Gezzarak the Huntress, Karrog the crystal giant, the heretic known as Darkscreecher Akkarai and Vakkiz the Windrager.  They will all need to be slain before Terokk returns to this world.$B$BYou will need the scrolls carried by the time-lost arakkoa to call them forth at the summoning circles in Skettis.  Bring me a token from each one.  These are powerful beings you will be facing; you would do well to bring friends.