Sheeeee has no pivot points on anything mind-affecting, she's been steering well clear so far. She might be able to do it by arts; this will inhibit mass production but she's not sure there's ever going to be a demand for mass production.
She gives herself a week and a half to get solid, sustainable, sufficient-to-replace-boats-and-horses-f
And from there she stares at her notes and thinks about walling off herself from the sliding of time, arts or arcana, either will do -
He does not try to swim it. Though Ossë always spares a bit of his attention for fishing stupid Elves out of the water, so it would not have been disastrous. He goes back to Tirion with his tearful parents and they have lots of long talks as a family and Fëanáro obsesses over time and whether he is missing out on it.
Bella is due in to briefly restore Miriel's memory before she has a mindshield down. (But she has a functioning watch, which is her first legit magic item, and she thinks it will help. She has another in her pocket.) She lands in front of the palace and goes looking for Fëanáro first.
"I'm sorry, if that helps. I got you a present, though." She digs into her pocket for the watch; it's a wooden bracelet with a flat rectangular panel in the middle of the smaller beads and numerals slowly changing. "It keeps time."
"I haven't fixed it yet; this is just a quick visit. You're welcome. I dug out the bit of a bunch of spells that makes them only last a certain amount of time, shrank it, and it runs that down so it's counting seconds and hours of the day, and then I stared at my knife trying to figure out how magic was attached to it until it made sense, and then I had three failed prototypes before I got these two to work. I got somebody who could see the treelight from the island to tell me when it was Mingling to set them; they flip over to zero when silver goes white and then count up until it happens again."
"...you do seem to be literally watching paint dry but I was imagining you had a reason."
She unhugs when he's done. "I'm working on the thing. I decided to do it by spell instead of by subtle arts, because it's really hard to do subtle arts on oneself and it admits of less experimentation, and I think I know most of the pieces I need to figure out."
She's starting from introspective understanding of what the sliding feels like versus its absence; she paid attention on the boat ride, and on her flight over here, to what the change felt like, and thinks she's identified - in hopelessly subtle-artsy terms, but she tries to translate them - exactly what's changing and by what avenues. She's heard of mind defense spells; arcana and subtle arts don't exactly interact, but they can both operate on the same basic stuff, and she's reverse-engineered what she remembers of defensive mental enchantments to figure out what the effects and required mana expenditure might look like. That tells her that she needs more than these three things she's sure are essential - probably - she might be able to make a stripped down version but only when she's seen one working in full -
"I'm not sure. I mean, maybe he could but it would be really hard to figure out and he has too much other stuff to do, or he doesn't know enough about my species, or something; he just said it was a general effect and he couldn't except me from it."
"I don't know either, but there could be a lot of it and I wouldn't necessarily have noticed him doing it by going and seeing him."
"Yeah. It won't take long. I can stay a few hours after that if you want me to."