PSA: We need to clear this up, "Toxic" =/= "OP"
a champion having a "toxic" design or ability does NOT mean they are "OP"
Toxic" mean they ability/kit is aggravating to face, regardless of its strength. even when you easy are winning. it still ruins all the fun in the game.
being "toxic" is NOT a representation of strength.
being "OP" or "overpowered" means something is TOO STRONG
a champion can be "toxic" but not overpowered. a champion can be overpowered but not "toxic"
toxicity depends on the "KIT" or ability, and how aggravating is is to face regardless of strength, the counters it may have, or if you are winning or losing. being OP just means it is "too strong"
for example.. right now
is very clearly "overpowered"
he has a bad design, becuase his kit is binary 0: i dont reach you and I'm useless" 1: i reach you and there isnt a power on this earth that can save you
meaning, if you make it so he can reach you. he is broken if you make it so he CAN'T ... he is worthless
this design needs a rework. not a buff or a nerf..
and because we are talking about toxicity i might was well bring in the most blatantly obvious champion that is without a doubt the most toxic champ in the game. 
regarless of his state. if he is weak, strong, or balanced... he is an absolute nightmare to deal with.
a absolrdy short cooldown
that also turns him invisible , invisible boxes that hard CC you, A clone...
his entire kit is bacially design to troll you.. and piss you off... and even when your winning he is a pain to face.
does he have counter play? sure he does, start
and sweep his blue buff at 1:15 to clear his boxes.
play a champion that can grant true sight somehow.
his counterplay although minimal compared to other some champs does exist.
the point is even when you play properly his mere presence in the game ruins the fun.
another example is
even when balanced.. his mere presences ruins the game. does her have counteplay sure.. can it make it fun to face him? no...
yet change one ability is yasuo's kit such as his dash (such as dash through his own minions instead of yours, or make it so he cant use his Q mid dash) and make his wind-wall unidirectional so if you can actually get behind it you can shoot through it. he would be fine
then there is the ADC champs who are ALL "OP" because their itemization makes it so. (and the damage creep from runes damn-well makes everyone OP) but we have to keep a reference point... so in relation to everything else in the game ADC are "OP".
but this has nothing to do with thier kit. save from a few outliers (im looking at you
) who could easily lose the reset on assist or maybe be given a partial reset on a kill and not a full one.. or maybe have the reset scale with the level of rocket jump.
being "OP" does NOT make you a "toxic" champion.
it has certainly happened they riot made an ability toxic during a buff, and that then made a champion "OP".
but "toxic" and "OP" are NOT flat out interchangeable.
toxic and OP.


OP: Original Poster
: giggling intensifies
toxic and op.
in my opinion is an example of a toxic, unfun kit.
The entire purpose of this champion is to splitpush and just annoy the hell out of the enemy team, constantly leaving him as a force to be reckoned with.
His ult means he's also able to 1v1 almost any champion in lane, or anyone that tries to stop his pushing.
on the other hand has a speed boost, a slow, a stun, burst, DPS (with ult and upgraded E), a silence for 0.25 seconds. and a shield. But he doesn't really do anything too well and just sucks now because of it. He's either snowballing and one shotting with his burst (which is what most people build him for now) or he's useless. He used to be able to get lich bane and be a DPS mage cycling skills and autos, or a full burst mage with utility. Now it's burst or bust.