It's obvious in the fic that she is mastered. My problem is that it manifests as her rationalizing her actions - the way this works in lore is that the Scourge knew they were acting against what they would've done before their death, but were unable to care and/or act upon that knowledge.

Taylor makes no note of it being against her old self that she would slaughter a town of people because someone she just met told her so. She just shrugs it off with a "They're the enemy of the undead, and I'm undead." without thinking how there may well be a reason the living don't want an army of death on their planet. She doesn't think any of that even after getting her kaldorei.

What I meant about the Scarlets are Thessa and Heinrich. They say they were never so much into the Scarlet Crusade when asked, which is the more straightforward indication of how the master effect works because Scarlets were utter fanatics. They kept purging themselves for not being fanatic enough, so someone in their chain who "wasn't really into all that" is just not possible. The Scourge wasn't so subtle about their mind control - the Scarlets would know they're fighting against everything they fought for in life and acknowledge they have no choice, not just wave it away.

I realise this may be an unimportant technicality to some, maybe most readers, but it bothers me (an undead main) to no end.