For the Necromancer Ascendancy, you have several key nodes that enhance your minions, and POE2 Currency Spectres specifically, as well as your personal survivability and damage output. Here’s how the Necromancer Ascendancy works in synergy with different playstyles and Spectre selections:

1. Key Ascendancy Nodes for Spectre Builds
As a Necromancer, the Ascendancy has several powerful nodes that directly benefit your Spectres, minions, and supporting mechanics. Here are the most impactful Ascendancy nodes for Spectre-based builds:

1.1. Unflinching Army
Bonus: This node gives your minions a huge boost to damage mitigation and defensive layers. Your minions gain additional resistances, which makes them tankier.
Synergy: Ideal for builds that prioritize minion survivability. This works well with Spectres that may otherwise be squishy, such as Flame Sentinels or Solar Guards, by giving them extra tankiness.
1.2. Puppet Master
Bonus: Increases your minions' attack speed and movement speed while also granting them the ability to deal more damage.
Synergy: This node is perfect for clear-speed focused Spectre builds. If you're using Spectres that rely on fast attacks or area-of-effect damage (like Redemption Sentries), Puppet Master will maximize their damage output and speed.
1.3. Mistress of Sacrifice
Bonus: Increases the life and damage of your minions while removing your own life regen. This node gives you a boost to both minion damage and survivability but sacrifices some of your own survival to maximize your minions' strength.
Synergy: Mistress of Sacrifice is a great choice for a high-damage Necromancer build where the goal is to maximize minion damage while relying on minion tanks for defense. This can work well with Spectres that need more damage to be effective, such as Void Golems.
1.4. Flesh Binder
Bonus: This node focuses on minion life and minion regeneration. It grants a significant life boost to your Spectres and zombie minions and can make them much harder to kill.
Synergy: This Ascendancy choice is best for defensive playstyles, where you want to increase the durability of your Spectres, making them more effective in tanking damage. Flesh Binder will synergize well with Spectres that act as your frontline, like Solar Guards or Doom Guards.
2. Synergizing Ascendancy with Spectre Playstyle
Now, let's take a look at how you can choose specific Ascendancy nodes to complement different Spectre playstyles.

2.1. High Clear-Speed Build with AoE Spectres
For high-clear speed and AoE damage, Ascendancy nodes like Puppet Master and Unflinching Army work incredibly well. They boost the attack speed, movement speed, and damage of your Spectres, ensuring that they clear large packs of enemies in a short amount of time. Here are some ideal Spectres for this build:

Redemption Sentries: They deal massive AoE damage, and with Puppet Master, they become even more efficient at clearing mobs.
Flame Sentinels: These Spectres can quickly clear swarms of enemies, benefiting greatly from Puppet Master’s boost to their attack speed.
2.2. Boss-Focused Build with Tanky Minions
For builds focused on endgame bosses, you'll want your Spectres to be tanky and durable, so focusing on Unflinching Army or Flesh Binder can ensure that they survive long enough to deal significant damage. Consider the following:

Solar Guards: Their high durability and good single-target damage make them ideal for bossing. Unflinching Army or Flesh Binder will boost their resistances and life, enabling them to survive even the toughest fights.
Void Golems: With Mistress of Sacrifice, you can boost their damage while ensuring that they stay strong in boss encounters.
2.3. Hybrid Build (Farming + Bossing)
A hybrid build requires balance in both clear-speed farming and bossing capability. Here, you may want to mix different Ascendancy choices for minion damage and cheap POE2 Currency minion survivability. This hybrid approach will allow you to adapt to both map farming and tough boss fights.