I’ve always hc’d that Lavellan does know a bit of magic theory but yeah, explained in a more ‘elvish’ way. So she has a hard time explaining it to Dorian or Viv but Solas can keep up and validate her theories

There's a pretty great Tumblr post about this:

Before they were abducted by the nautiloid and eventually reunited with Mercy, though Mercy didn’t remember them. They didn’t get back together in the end. Instead, our resident bisexual disasters Mercy and Keres ended up with Astarion and Gale respectively. And they all lived happily ever after 😌

Minthara called for Mercy to be found and executed, and for Keres to be killed with her, as she felt their affair was a betrayal. Keres volunteered to find Mercy at all costs, even their own life, bc they still loved Mercy and believed something else was going on. Keres spent two years searching—

After a while, around Mercy’s 85th birthday, the urge in her blood began calling to her. After an evening with Keres, the urge took over, & she slaughtered half of her adoptive family before fleeing to the surface. Keres witnessed the murders but couldn’t stop them. Minthara was furious.

Keres worked their way into Minthara’s good graces after a decade or so, becoming one of Minthara’s personal guard, and they eventually caught Mercy’s (then known as Malafae) eye. Knowing this wouldn’t go over well with Mercy’s adopted sister, the pair kept their love affair secret for years.