Umm… Play them all!
Necromancer is primarily an AoE condi-pressure profession. It does huge amounts of damage to large groups of trash mobs but has always struggled with low burst damage. Combat mobility is extremely limited compared to other professions but has higher vitality and Death Shroud to soak up more unavoidable damage. You can teleport to an opponent but there is almost nothing you can do to get away.
Fear is an interesting skill. Necromancers have several ways to apply it but they are always relatively short fears and they can be resisted so, at best, it is a minor gap opener and the only consistently reliable one Necromancers have. Instead, Necromancers use fear to cause damage, when traited. That is the infamous fear lock players forget about when not expecting a Necromancer to fight back.
Necromancers used to be easy prey in wvw because of the poor combat mobility skill set and huge amount of time it took to build up dps. I am not sure that is the case, anymore, but they also get targeted because conditions can win a fight if the opponents neglect condi-management in their builds. Chill, blind, weakness, immobilize, cripple, and vulnerability do zero damage but can really wreck a team that does not sufficiently plan to go up against those conditions. Poisons and bleeds both sneak up on a person and then there is Terror that can hit for fair damage at inconvenient times.
Necromancers did not use to get the dps up until long after a Thief had already unloaded all the burst damage. While the Necro now has better direct damage, it still retains some of that slow start so the profession was designed to survive the initial clash and draw combat out longer so condition stacking can start to mean something.
Minions are an “easy button” for Necromancer because they are summoned mobile weapon systems you can just forget about if you are new to the profession, though really good minion master play takes a lot of skill because they are difficult to pull the most out of.
Play is very different between Necromancer and Thief. There is no escape button other than sacrificing an immobile minion, which takes planning and is conditional. Be prepared to be bounced around like a ping pong ball by knock-downs, knock-backs, tosses, etc. Necromancers are durable for a reason so do not expect the higher vitality and DS to go unused.
