azir has a rework planned, but how did he get so buggy?

So ,from what I can gather as a wood division player (ranked people tend to be very...sensitive. so I don't play ranked) was one of the best LCS champions due to his kit and what it can do with the mechanically capable players (or something like that) but was horrible in lower ranks due to him not being able to do too much without practice. so he was nerfed or changed so he can be played in all ranks but eventually just got really bad. he is kinda like . they aren't very good in a lot of cases, but I like playing all of them.in fact I think skarner is still my highest mastery character... But at least ALL of them are playable and have some (sometimes silly...) strong points. a fed skarner is basically but with CC and can pull you turret to turret morde has his ult an shields,illaoi can destroy people with her ult. and mundo can ult/in general have dumb health regen. but I sub him out with who has high base regen so you can go resistance/regen items and nobody notices and buys . back to the point. they are are playable,have strong points. azir has strong points but PLAYABLE is debatable. a friend said "it's been a while since you played azir. I wanna see" so I went to do that. my Q a lot of times didn't do damage,specially if It went through somebody dashing example being . my R a lot of times would target in a totally random direction. I was aiming towards a raptor camp,it pushed everyone to the right of me rather then the northwest direction I was facing. that wasn't even in the opposite direction, just a totally random direction. at one point a teamfight went off. I had to soldiers out,one under turret another in the fight to poke. I used my E to go to the turret from where I was standing,directly over the turret soldier, and it sent me to the one in the middle of the enemy team. I get that riot made changes but idk how you manage to make such random bugs. generally its "this doesn't hit that, this fails to spawn, this bugs in high latency enviroments" but the ult, aiming in a completely random direction,and the E aiming at a random soldier? The main question being when did this all happen cause there was a point I know of where his AA's would straight up miss.