Nighthold means a potential mix of both Destruction and Affliction. I personally couldn´t fight all the bosses (even in Normal Mode) yet. For that, I cannot guarantee you if I really like the following talent specs for each encounter.
Nevertheless, I really like to switch specific talents to cope with new challenges. In general, I´m not a big fan of Channel Demonfire (Destruction), so I´d love to check out Affliction in a lot of situations. Of course, this all depends on your own playing style and how much damage you´re able to do.
Further more, a friend of mine linked me the following new concept of raid guides and I really like it. please give it a try !
Well, thanks for reading and enjoy the following lines !
Nighthold – Both Destruction and Affliction
Chronomatic Anomaly Destruction
Spellblade Aluriel Affliction
Star Augur Etraeus Affliction
HIgh Botanist Tel´arn Destruction
Grand Magistrix Elisandre Destruction
Source (Picture ; free accessible): pixabay