Nice concept, only that I think there are some things that will bring it down to Rito's eyes
Even though your story is good, for them it will be not: lately Riot has stated how "plot is overrated" in the sense that they decided to make champions following a certain factor. The factor I'm talking about is about not making champion following a general way (which is, make a character with his up and downs), but to extremize that shit
Give a look at all the last champions: after Yasuo, there are ONLY champions with one-way-set personalities/stories (except Azir (but he actually gets pretty much close to it))
-Vel'Koz is about knowledge's desire
-Braum is about "gentle giant"
-Gnar is about "cuteness"
-Kalista is about revenge
-Rek'Sai is about land sharks (pure animal)
-Bard is about "cosmic energy being"
And lastly comes Ekko, which is about "swagga-boy-hood" cool-version.jpg. Basically, what they search for their characters, in my opinion, is more about unilateral settings so that people can easily symphatize with the one they think rapresents them the most instead of making someone "normal"
An example
Take Talon: his story is about him having always fought for himself and now forsaking the chance to go back to that state to instead honor his respect for a single person. However, if you ever play him, his lines give out nothing of that
Take Tristana: they basically erased her story and completely saturated her lines about her being a sassy army girl, so that whoever has his liking about this kind of thing can find the champion that completely matches with his tastes, without leaving any bad ones in his mouth
Said this, your story is fine, but I think the setting is such that people can't get captivated by it (look Quinn and Valor, nobody worships that shit)
(I hope I explained what I meant properly, since it is a hard concept to explain in the way I feel it. If something looks strange, I'll try to explain it into another way)
(PS I might be wrong too btw. I'm writing this to also see if what I'm thinking is correct (or close too) or is something that is inside me on solipsistic levels)
About their abilities, I find the Q problematic, since it is quite similar to suppression and usually suppression abilities shouldn't be regular ones (they are mostly ultimates)
Unless we're playing Dota 2
Also, the passive and the R don't go well together: the R works at his most when they're both distant, but if they're distant their passive will take their HP. In this way, there is no reason to actually get distant since otherwise you'd be losing HP, but if you're close then the ultimate shouldn't be needed as much, since it's channeled
Also, last thing
Swords are overrated as much there as here with RHGs :T
Something more defensive might be better, considering his role. Unless it is not a normal sword (like Diana's one)