Leliana and Wynne turning against you if you taint the Sacred Ashes
There are several points in the Dragon Age series in which a party member can turn on you, but none have ever been quite as shocking as when the religious bard Leliana, and otherwise kind-hearted Wynne, turn on you if you taint the Urn of Sacred Ashes. This is a crime against one of the most prominent doctrines in all of Thedas, and bringing two of the most devout members of the party to watch is bound to cause drama, but Origins takes it a step further by having both of your teammates take up arms against you.
It doesn’t matter how far you’ve progressed through their personal stories, or even if you’re involved in a romance with Leliana; faith trumps all other emotions here, and you will have to strike down your allies. You’ll face plenty more betrayals during the Dragon Age series, but Leliana and Wynne’s heel turn is still one of the most sudden and violent.