Torbjörn is a man of strength, loyalty, and dark secrets. (Sounds good so far. It's not the most gripping beginning, but not bad either. (Now that I went back and read some more, the sentence in blue sounds like a better hook to me.)) He was once one of Odin’s (Who/what is Odin?) chosen, a true berserkir (A what?) with the ability to shape shift into a bear. He fought for on the side of justice until he was killed in battle. (What battle? Is he a warrior?) He is made whole (How?) and hale when a Valkyrie (A what?) arrives to deliver him to Valhalla (Is that a person or a place?). But at that moment, the signal (What signal?) is given that Ragnarök (Wait. Who's this now?), the Norse apocalyptic end-of-the-world has begun (I got so many questions from that last part. Like: WHAT? Why an apocalyptic world? How did a signal say that? Why is it the end of the world? What's going on?). The Valkyrie (I can't remember if you've said this word before or not, but I don't know what it is.) ascends to and leaves Torbjörn behind, caught between this world and the next (What world would that be?). Alive and immortal. Interesting.
So, some pointers:
-Explain everything you introduce into the query letter. If not, the agent will get too confused and not want to read on. Tension can build naturally if you tell it. Forced tension, also known as false tension, is drama that you never explain and it only leads to confusion.
-Mention maybe 2 or 3 new characters or kind of people. Maybe 4 if you're stressing it. You mentioned 7 in that paragraph. (I bolded them for you.) An easy way to know who to mention: the main character and the protagonist (who I'm assuming in to blame for the random end of the world thing?)
-Delete extra filler words like "on the side of". If you can say the sentence shorter and still make sense, do it.
It honestly sounds interesting so far, but I'm just super confused on what's going on. I know you want to say everything about your world to try to pull the agent's attention, but mentioning everything in such a small amount of space is overwhelming. Save some of your amazing plot twists and details for the novel. : P
(Also, here's an advance tip because I think you can do it: Add more emotion into your main character. Sometimes this is introduced by action.)
A few millennias later, (Whoa, that's a time jump.) in late ninth century Scandinavia, Torbjörn is working as a master hammer smith (? He chose to do that while the world is ending? What was he doing before?). He is hiding from his past (What past?), careful to keep the beast within subdued lest (Use more common words just in case. Like not everyone knows what "lest" means.) his curse be discovered. This paragraph, by far, is better than the first. I'd cut out all the background of paragraph one and mix some of the details like turning into a bear (and the end of the world) into this paragraph.
Kiersten is a woman desperately trying to remember her past. (How did she forget her past?) Her village was slaughtered by a band of men wearing wolf pelts, her family killed. (If her village was slaughtered, her family should be dead. If it's already known, don't mention it. Trust that your reader understands.) She escaped the carnage at the cost of her memory, and very nearly her life. Tip #1 Never use the word "very". It's not a mature writer's word. I can explain more on it if you want. Tip #2 Explain how she lost her memory. Like how did escaping get her to lose it all? Tip #3 By the way, so far, we've been in Torbjorn's POV, but this is in Kiersten's POV. Even though it's a good paragraph, I'd stick to one POV. You can mention Kiersten still in Torbjorn's POV.
Kiersten and Torbjörn finds Kiersten come together when she washes up on the bank of a river, barely clinging to life. Kiersten’s resemblance to Torbjörn’s lost love hits him like a fist to the gut (What resemblance?). and He finds he cannot stay away from her. In her arms, his heart, shut down for centuries, (Wait. When did his heart stop? I thought it beat again after he became immortal? Also, what happened to the end-of-the-world thing?) begins to (Try to never use the words "starts to" or "begins to". Your writing flow will improve without it.) beats again. Lust and desire stirs a passionate love that burns hot between them. Wait. Why does she fall for him then? And you're getting distracted from the plot. What happened to that war? (Lust isn't love though, which makes me think they'll break up in the end.)
When Kiersten’s past catches up (Wait. How did she remember her past?) with her and she’s captured by the men who slaughtered her village, Torbjörn is forced to expose his curse at the risk of losing her and everyone he loves. I'd reword like: ...is forced to choose between exposing his curse or losing the woman he loves.
I am seeking representation for (Don't state the obvious) TORBJÖRN, an 80,000 word paranormal romance, is a standalone with series potential. According to your website, you’re seeking paranormal romance submissions, and this story would be a good fit. As I mentioned before, don't state the obvious.
I am a married mother of four, and up until a few years ago, had never written anything more in-depth than a grocery list. I’ve cut my writing teeth on several short stories and one romance novel, all self-published on Amazon. This paragraph will HURT your query SO MUCH. Let me explain: 1st - Mentioning how you never wrote for a long time makes you seem unqualified. 2nd - Agents do not care about self published because, honestly, self publishing is the easiest thing to do. Anyone can self publish now. If you were self published and won all this rewards with a lot of great reviews, that's another thing. But agents and publishers don't care about self publishing and kind of look down on it.
So, I know this is a lot of words, but don't fret. I saw a lot of potential in your writing and wanted to give you the most options and suggestions as possible. Your novel sounds super interesting. The plot's cool. If you want, I can direct you to a couple of sites to help. : ) You can do it!