Needle her about her failure to stop you

You start to slowly circle Vex’ahlia, knowing that for the Ranger being in control and able to see her target was one of the things that gave her confidence. Hell you felt the sting of her arrows, so you, were aware of how dangerous a calm collected Vex’ahlia could be. Which meant you had to break her cool.

“You know we found your husband’s body little elf girl. It was kind of hard to make out considering how splattered he was. But we found some white pair and a pair of glasses that had been shattered. It must have been awful, falling whilst the fire consumed his flesh, knowing he was a failure. A monster who’d failed you..”

Vex’ahlia had gone entirely still. The muscles of her back locking up tightly as you insulted her dead husband.

“Your brother came back as well, it was after you were knocked **** but the Raven Queen sent him through in the hope that his love for you and Keyleth would prevail over the darkness. He failed of course, last I saw him he was weeping and broken over Keyleth just before a pair of my zombies dragged her away. He was screaming...screeching...pleading for them to take him instead to what fate awaits her. I banished him myself, the Reality Marble gave me all the power I needed to make sure he will..never..be able to return again.”

Vex’ahlia was visibly shaking with rage now. Her teeth clamped shut over her teeth.

“Oh and your father...he threw in with us. It cost him of course, your stepmother is right now serving as a cheap two copper whore to the lowlife scum of Shadycreek Run. But Syngorn survives unscathed, all it took was the enslavement of half their female population as the lowest of whores across the land...and your father approved it all. He said it was a worthwhile trade.”

At this last, Vex’ahlia explodes in rage. Writhing against her bindings with all her might and screaming incoherent hate from behind her gag. You can only grin and watch in amusement. This was just the first step on breaking her down, making the cool half-elf Ranger lose her head entirely.