Played Castle Naerytar last night and I had intended letting the group (Paladin, Rogue, Warlock, Sorcerer and Cleric Level 5) throw down briefly with Rezmir and have her take a chunk out of them and cast her darkness and excape through the portal....
They slaughtered her! I rolled poorly on initiative and I had to cheat and make my attacks at -36 hit points! They have the mask, the sword and the claws now so fair play to them. And this was a relatively tired party.
I sure as "heck" won't be helping them with the Glazael!
Now I want to add " Boost Initiative" to the abilities of a 5e Warlord... 
Erm, did you remember her Legendary Actions (due the mask)? Only because you rolled badly at initiative doesn't mean, that she can't use them right away. ;)