I'm not particularly keen on their kits but I think the back story of each and how their relationship kinda forms is pretty cool.
So the kits aren't exactly good, kinda like how her Q is just a worse version of Zilean's E, and his corruption is basically an alternate Twitch passive. So those would definitely need to be reworked imo.
Backstories / Current stories(story line in general): I think it was a very fun read, and definitely agree with the other guy about writing a novel.
[slayer-pantheon-popcorn]
To be fair I skipped bits and pieces of the actual dialogue in his story which I already read in her story, so that part was kind of repetitive, but it makes sense why it was done like that.
I've only done like 2 back stories for my (currently)42 champions.
Umbra, The Grim Puppeteer
Zaun/Shadow Isles based champion.
Terunis, Aspect of Runeterra
Piltover/Mount Targon based champion - this lore actually moves into a story that another person is writing.
I think they're interesting reads, but I wouldn't consider myself great at writing... Not your level anyway.