I'm not sure if these will be exactly what you're asking for but there's a few anime and light novels that touch on the topics you mentioned.
You could try death mage doesn't want a fourth life. While it doesn't have a mc hero, it does have a world set quite a bit after a demon lord invasion...
I like how Arctic water looks under the thick sheets of ice. I makes for a beautiful blues above and a scary dark bellow. Reminds me of that moon that's supposedly got a ocean under its ice.
That or kelp forests, so much life above and below the water. I guess as a part of this but also...
When I'm writing a scene, I tend to do a little research first. Find the most relevant details, find a few images and write about the more unique or different features.
Of course sometimes you want to get to the plot so you can either give the name. For example saying elevator or Pendant...
Sometimes when writing is too difficult or ideas avoid me, I take a break. Read about interesting things like did you know there's a snake where the edge of it's tail looks like a spider?
If not looking things up then go outside, eat somewhere new, or go some where with old or unique...
I enjoy mother figures, characters and MCs because they're often super supportive and always try to knock their children out of funks.
Personally a mother mc in fantasy can be interesting because you get to see how their kids react and treat her. Plus often in anime to a comedic effect the...
If it's a character the mc idolizes as a hero or the population admires then maybe, maybe if you're planning to have some of the plot be driven because of the character's death.
Radical or angry groups form and take action that changes how the mc sees people or the world.
Or at the very least...
If the character is new to being overpowered then you can do things like having opponents be better fighters then this character. Can't hit if they dodge, out maneuver and redirect their op attacks.
You could have a growing phase too, their attack is too much they even blow themselves away...
I rewrite any chs that don't feel right or could be better. Then I add it to my backlog and if future chs don't mesh well with the soon to be released CH then it gets edits and parts rewritten.
Granted the only time I ever deleted a CH was because my computer had shutdown and didn't save 90...
I've only added art in special chapters after hitting personal goals. A sorta art dump/hey this is how that works or looks like.
While your audience might be annoyed, I would hold back to only 2 pictures. So you can focus on your writing more, editing and plot development.
Then maybe either...
I consider it future proofing your work. What if down the line you decide to make an official novel of it or a new reader comes in? If anything you're helping new readers and giving anyone that re-reads your work something extra.
I try to edit my story every now and then, adding details or...
Even if you factor out all past and current pollution to the ocean, it's getting hotter, currents changes and the ocean can get more acidic. Certain marine life will die out like corals. Plus considering invasive species that humans actively try to remove like lionfish and purple sea urchins...
If you want to, you can even use some cultural thing to signify they’re adults. Like growing out hair a certain length. Some cultures in real life use tattoos and other markings to show they reached adulthood and even if they're married or not. Then just have it so kids of the race don't have...
I've put random sketches in my story in side chapters or when i hit a milestone. Generally it gets more attention. i feel it gives my audience a chance to see what I'm imaging for my characters and creatures.
I've seen other authers here use either Ai, paid artists to do character and...
Uh, but do you cry or feel shocked when you hear about someone you don't really know dies? I've only cried when my grandparents died.
Granted in most stories, the mc knows about the side character and might’ve hung out a few times or even received advice from them. In that case I guess out of...