Boss encounter: phase enemies or all at once?
My party of 5 players, level six, soon got another boss fight coming up, right after a long rest (and no risk of danger afterwards).
They will fight:
A performer maestro
A human death cultist (flee mortals)
A juvenile shadow dragon
Two (might keep it at 1) Ettin
3 Spies
And 10 CR1 minions using minion rules drom Flee Mortals.
This puts the encounter just in deadly.
For the story, it makes sense that all enemies are there at the start. I will also put this all on the table before they'll arrive (we play live) and I want to see the look on their faces. However, I feel like I 'should' phase the enemies, cant tell why. Would you guys say its okay to start with all at once?