They keep Strickler in the dark up until Jim, Blinky, and Douxie arrive back on Earth. The whole group and friends (Steve and Eli have been recruited by this time, Notenrique, Archie, Stuart, maybe some others they accumulated by this point) gather at the Nunez house for a welcome back party. As Barbara, Stickler, Aja, and Archie arrive, Aja changes back to her Akiridion form in her excitement. Once that shock wears off, Stickler looks around to see other aliens, trolls (including that runt of a changeling he's been in charge of), Archie transforms to his dragon form. They have time before the guests of honor touch down and it's mostly used to catch Strickler up on what he's missed.
Claire misses her chance to intercept the goblins stealing her baby brother, not that she was entirely sure when that would happen in the first place. Eventually, she has to tell her parents, but for a while she lets Notenrique have his peace. "I'll give you actual food, but I'm not changing your diapers," she states the first time she drops a bag of fries into his crib.
With the amulet in his possession, Toby has to take on Trollhunter training. Problem is, there's no Blinky to train him and no Hero's Forge to train in and no access to the ghost council. Fortunately, he has Varvatos to train him in the ways of a warrior. He and Aja help Toby build up his fighting skills and they make a habit of finding battles to fight in the night in place of the "answering every call" tasks he would normally be put on in Trollmarket.
Aaarrrgghh uses what leeway he has in Trollmarket to sneak in there and take what he can from Blinky's library. While he doesn't know what the kids will need in their studies, he does know Blinky's books have been of help before.
Krel seeks out the other wizards of Arcadia. He picks up work where he left off with Douxie in the other timeline, finding unique ways to combine Akiridion technology and magic. It goes a long ways in helping him compensate for what he doesn't have on Earth - their ship didn't come with them and Stuart only has so much hoarded away.
Claire is down a wizarding teacher, so she has to mostly study on her own. Archie grants her access to the bookstore so she can study the materials in there and he guides her the best he can. She tried getting the other wizards in town to teach her, but they're mostly of the opinion that shadow magic will turn her into the next Morgana and none of them want to be a part of that happening.
On Akiridion-5, Blinky tries to assert himself as an advisor. It kind of works. The Akiridions grant him a certain level of respect due to his four arms, yet it's hard to trust someone that showed up right when their princess and prince disappeared. He ends up telling a lot of stories of Earth and updating their system's archives about the planet. And when he's not doing that, he's focusing on continuing any of Jim's studies he can while they're down all their typical resources. At the very least, the two are allowed to observe the warriors at training (they won't let Jim have a weapon just in case the group ends up being enemies in disguise).
Jim works on prying information from anyone and everyone. They have little to no idea of what happened to bring Aja and Krel to Earth in the original timeline, so he's looking for any sign that will help him help Akiridion-5. It puts a lot of suspicion on him. By the time they begin their voyage home, he's made basically no progress in figuring out the mystery and it leaves him feeling paranoid about leaving the planet. It's not until he convenes with Aja on Earth that he learns Varvatos was the key to the invasion that initially forced them to flee.
Douxie has a grand ol' time on Akiridion-5. Everything he was working on with Krel gets to be shown off to the King and Queen and anyone that will listen. He's easily the favorite, especially when it becomes clear how closely he worked with Krel. He spends his days dazzling people and strengthening the planet's defenses for their departure. Any threat this side of the universe is going to fail at penetrating his magical barriers.
Toby is the first person Jim hugs when he gets home <3
*if anyone feels like writing for this AU, I fully encourage you! Just give me some credit and tag me/send me a link so I can read it :)