She's deputized Zann to make the Reverend Mother as uncomfortable as humanly possible, a task to which she has taken like, well, like an elven maleficar to fucking with the Chantry. This leaves Jahenna with free time to spend on reading, battle drills, and- oh for fuck's sake.
"My liege," nods Jahenna. "To what do I owe the honor?"
"Just checking in. How goes it?"
"Just polishing my armor, sire."
"Excellent!" Cailan sits on a tree stump and starts- talking at her.
"Maker's breath, look who it is, my goodness, it's Duncan and some new recruit, I simply must go meet them so sorry to cut you off." Jahenna takes off at top speed, leaving Cailan in a cloud of thinning dust.
"Duncan. Maker, Andraste and all her fucking cousins be praised. His Majesty is trying to talk to me. He- Andraste's lacy underwear, he followed me. If you need me I'll be hiding in a river." She takes off again.
"Good day, Duncan!" hails Cailan. "I see you've a new recruit to your number! How goes it, friend?"
"Ooh. It's a party! Don't worry Tev, I'll leave some for you. If only because I don't think you could get blood out of mine after I'm done with them."
...Jahenna mouths Later. It appears that she may disagree with Duncan's judgment on this!
"Come along, children," says Jahenna. "Auntie J is going to take you out hunting, won't it be fun."
Not waiting for an answer, she drags him behind a convenient tree.
"The Joining is where you use the blood you've collected to essentially turn yourself into a little bit of a Darkspawn. It's got a few side effects, but none that are particularly prohibitive apart from a somewhat shortened lifespan, and it's the only way to end a Blight. And there's a death rate, but out of the three of you only Morty is at all likely to incur it, because you're a brick fucking house and Zann's a blood mage."
"For whatever reason, the recruitment rate goes down when you tell people they're turning themselves into monsters and they're a certain amount likely to die in the process. Fancy that."
"Oh, a moralist. Lovely. You know how there's an archdemon, and we're the only way it can possibly be killed? I think that's a pretty fucking good reason."
"Because you're in no actual danger and you're clearly stubborn enough that it could have gone very, very badly if, say, we sprung it on you with no warning and you disagreed with our assessment. Forgive me for being inconsistent in the interest of keeping a half-bronto elf from lopping my head off."
"You are still going to go through with the Joining, right? It really is necessary to saving Ferelden and probably Thedas in general. And there's fringe benefits."
"My sword is a couple of centimeters taller than I am. If you think a woman my size should be able to lift that thing, let alone murder with it one-handed, you are incorrect. Let's see... perfect metabolism. Ability to sense danger, plus various boosted senses in general. Increased sexual stamina, or so I've heard. Immunity to disease, courtesy of the Taint seeking it out and murdering it. You won't age until the day you're supposed to die. Any latent magical abilities you may have get heightened. It's a nice package deal all 'round."
"Well, save the world for its own sake then. I'm not stopping you, that's why I signed on."
"In fact I think the fringe benefits are a little worrying. If I get any stronger I'm going to have trouble opening doors."