The problem is the alignment system is not exactly precise. It turns out trying to dictate complex philosophical and moral realities into a two-axis system is hard. Who knew?
For example I could see a reason to claim Jhin is Lawful Evil, Neutral Evil, and Chaotic Evil. I could even see a reason why someone would claim Jhin isn't evil at all. I'd think they were crazy, but I've seen it done before.
It also doesn't help that the system itself has been rewritten a few times since its first introduction.
So, if you want to know, I'd ask you a few questions.
On the Lawful/Chaotic axis, which do you consider more important, following personal codes or following societal codes? This is a huge distinction, if you just look at one of the most common examples given in this system: Robin Hood. Robin Hood broke societal code repeatedly, stealing from the rich and fighting King John and the Sheriff. So, clearly that's Chaotic, right? But John's reign was legitimate, and Robin was gathering money not just for the poor that were being unjustly taxed, but to raise money for the return of the true King Richard. So taken that way, he's clearly firmly Lawful. Honestly, he becomes one of the most Lawful characters in the setting. Even Friar Tuck compromised his morals a few times, Robin never does.
What is Good/Evil? If someone thinks they're helping people but is really making their lives fundamentally worse, or even kills them are they good because of their intentions or evil because of their actions?
What is amoral? Can there be creatures above good and evil, or is that just an excuse for the evil who don't wish to be judged?
Anyway, if I would go what I view the characters as (and I'm sure many would disagree for the reasons I listed above) it would be something like this (just posting characters I have a decent grasp on):
Aatrox: NE
Ahri: CE but trying to repent as she gains humanity
Ashe: LG
Aurelion Sol: TN with some evil leanings due to apathy toward killing lower lifeforms
Azir: LN with maybe good leanings due to trying to free his slaves
Bard: LN entirely gut reaction. We don't know his motives or what the hell he's doing, but he seems to have some code for his actions
Brand: CE
Braum: LG
Cassiopeia: NE
Cho'Gath: NE
Darius: LN with both good and bad leanings depending on your thoughts on military expansion
Diana: CN
Dr. Mundo: NE
Draven: NE his job is necessary, but his obvious sadism with it pushes him to Evil in my mind
Ekko: CN with Good leanings
Elise: NE
Fiora: LN based solely on how seriously she takes the rules of dueling.
Gangplank: NE
Garen: LG or LN depending on further details
Gnar: CN
Gragas: CN
Graves: CN with some evil leanings
Illaoi: LE with neutral leanings
Jhin: NE
Jinx: CE
Kled: CE
Leona: NG as a child LN with evil leanings as an adult then unknown after possession
Miss Fortune: TN with maybe more evil than she would admit in her
Pantheon: little bitch
Shaco: CE
Shen: LN
Swain: NE with lawful leanings (entirely based on my interpretation of him, I will admit)
Wukong: CN with good leanings
Veigar: EVIL!!!!
Zac: CG
Ziggs: TN despite his penchant for explosives I don't think he's ever done anything good, bad, chaotic, or lawful. He just likes explosives