If you know the source referenced outside then you should have known what her 'stroke' was about? interrogation. And the mystery of their mutual shared interest when operating Knights of the Shield given it was still an organization corrupted due to the influences of Gargauth where she is was the leader of.
Most of the companions only end up revealing the things dues to circumstance, astarian? you caught him trying to dine and dash, gale? nuke isn't satisfied with your sacrifices, shadowheart? laezel found out she's a thief, wyll? mizora thinks its funny to punish him in front of you. Saying they reveal it to you due to trust is understating it.
And what is this evil manipulator trying to get you to do ? become the hero of baldur's gate by defeating the cult of the absolute? pure evil. He isn't good for sure, but no more evil than the kind of people you help already
