Galaxy Conquest

@aaronlinds238 Sith Trooper does not regain Protection. He gains Protection Up, which is a buff. Shock from Dooku will prevent him gaining the buff. Shock will also prevent health recovery.

Strength of the Void does not do additional damage to enemies, it means that your characters heal for 150% of the amount of damage they do. Eg, do 1,000 damage, regain 1,500 health. Again, can be prevented by Shock. 

Dooku can also Stealth that entire team except Sun Fac, and stealthed units cannot be countered. Sun Fac can inflict Daze, also preventing counters, and removes buffs with his basic.

However, it sounds like most of your issues stem from not knowing Nute Gunray's Kit and aren't staying on top of Extortion. I'll post a link to the kit below, but in brief: units that end their turn with Extortion dispel all their own buffs and pass Extortion on to an ally. This is why Sith Assassin drops Stealth. It also could explain why you aren't seeing the Protection Up buff on Sith Trooper, as he'll gain it then immediately lose it as his turn ends. Sounds like Sith Assassin is killed due to the 20% Max Health damage to all units with Extortion from Nute's special "Motivate".

Nute's kit: https://swgoh.gg/characters/nute-gunray/