here's my rito ples to fix your current mess of spaghetti code pronto
I'll be referring to my last game in which I was a lulu, you can check if you like but needless to say it was a shitshow. multiple things stood out to me including: shield not blocking damage if it was cast any time less than a second before said damage was taken, q would not slow for the full duration (sometimes when I checked the enemy portraits the q would apply the slow for around 1 second and then immediately decay to 0 while the slow lines still trailed behind them, sometimes they would just not get slowed at all) ult knockup would not interrupt dashes though maybe it just doesn't anyway, and polymorph would just do jack and shit. Not every time, mind you, but enough that I really started to get pissed off when I played a fight perfectly only to lose it because my ult would go off into oblivion with no evidence other than the brand spanking new cool down to show it was ever there.
I noticed this most with the tryndamere who could be polymorphed, wait a good half second (I didn't just plushify him mid dash), then spin in while in rabbit form, use his slow and throw in a few autos that hit like a truck as he tends to do, and then the polymorph would end. other times I would exhaust him and he would still crit for the full amount. I actually had a gague with the garen who would attempt to tank him through his ult/GA/bullshit lifesteal and other things. his dps would drop by exactly none while exhausted.
I'm not crying about tryndamere here, I actually don't mind him so long as I'm able to shut him down, but when spaghetti kicks in and riot doesn't care about making their game work before making their game flashy and he just mows down my teammates while clearly he should not be able to, then I get a bit salty.
Average ping 40, didn't go above 80 which is pretty standard for me. I defy explanations other than riot just doesn't care about stability which is confirmed every time I see in the patch notes "oh and we fixed this ONE more skill shot to match the hitbox because for some reason it didn't before we are competent devs believe us please!"