Sleipnir was an unplanned accident, resulting from Loki transforming into a horse to seduce a giant's workhorse to prevent the giant from winning a bet with the gods. Loki only meant to distract it, but as often happened when Loki was involved, things got out of hand.
Two years is pretty standard in the civilized world. Of all the developed countries, only the Fractured States demands you be back on the assembly line as soon as the umbilical cord is cut.
I haven't read the novel, and I don't think he's done it in the manga, but one of the basic premises of the story is "barriers can do whatever the maker wants them to" although most people who can do barrier magic don't have nearly protag's mana pool to draw from.
He can though?
"Oh, you have a disease."
makes a barrier that kills the disease pathogen and does nothing else, swipes it through their bodies
"Fixed, now please let me slack off."
Here's one of the classics: Remember to use the staff on the summoner, not the behemoth. It'll break his concentration and the behemoth will do the rest of the dirty work for you and then piss off back to wherever it came from.
The thugs died so fast they might not have noticed they were dyeing. Dario got to suffer a bit because he directly threatened Luna. These two are going after Theo, so Helvi is going to take her time to savor their torment.
I'll borrow a quote from a certain maid dragon for this one.
"Choose your next words carefully. I might return your soul after I finish breaking your body."