OP vs toxic, learn the difference.
A parable
Jimmy and his hot sister Sarah both go to play soccer with the guys down at the field.
when Jimmy plays soccer he will literally steal the ball from his teammates He will just kick the ball as hard as he can and try to score a goal from anywhere usually missing Jimmy likes to kick people's shins and hurt others to get the ball Jimmy will cheat anyway he can, sometime he trips others Jimmy is strong earlygame but later in the game he hardly even plays Jimmy lategame will get the ball and just stall them out pretty much refusing to play or let anyone else play Jimmy never passes EVER
Jimmy is toxic, meaning he's bad for the sport in general Jimmy is not OP, really he's just an asshole he's not even that good at the sport
Sarah is hot and she's one of the few grils these soccer nerds will ever get to talk to because they aren't cool like the actual local soccer team. But since she plays with them other girls be like "ermagerd I wanna play too" and suddenly there's a lot of players for both teams. A bigger field is needed Sarah's team always mysteriously wins no matter what. Maybe she's that good but she runs slow and misses 9/10 attempts at goals Sarah always wins but she is NEVER a bad sport and loves to pass so everyone feels included. Sarah isn't very good at soccer but she runs track so she's able to stay in the game for a full game instead of just turning into dead weight lategame.
Sarah is OP as shit, meaning she seems to win even when she REALLY REALLY shouldn't be winning Sarah is not toxic, she's great for the game. Maybe needs some tuning and practice but nothing serious. In fact she attracts more people to the game.
here are some examples of toxic champs

It doesn't have to be OP. It just has to have mechanics that say terrible things like
- don't play
- don't try to play
- don't breath
- don't ever blink
- lol you tried to play you get punished way too severely now
- no, your choices didn't mean shit I'm just going to heal it off and laugh at you as I continue to drag the game out into oblivion
- I'm just going to abuse this annoying playpattern until you rage and never want to play again
- I'm just gonna shit all over you and then stop playing halfway through the match
here are some examples of OP champs

there's probably more but these are champs who are given way too much to abuse often because of something weird in their kit. OP, as opposed to toxic, means that they do something that actually "dictates" the outcome of the game rather than simply make it less fun to play. You don't have to be OP to be toxic or vice versa. Oftentimes these champs will simply be things that can't really be balanced or are a work in progress.
I think they nerfed sol already but according to riot he was OP and just most normal players couldnt really abuse it coughscripterscough and yes, ashe always has been and always will be OP as shit, deal with it