If supports become viable in other lanes they are nerfed back to bottom
If mages become viable supports they are adjusted to function well as a support. What is this unfair bias Riot has against support champions. Either get the damn mages out of bot lane who make playing Leona impossible, or make Leona top viable. It's really not fair that damage bloating 'supports' get to be played viably in bot lane, but when Lulu, Sona or Karma become viable outside of bot lane Riot nerfs them back into it.
He would basically free win every trade top lane with his W and sheen combo and you couldn't even fight back. Even when you did he would have a large AD steroid and massive damage reduction. Going back even further he would be able to gank you behind your tower at extremely early levels and live.
She would pretty much have all of her strengths but amplified much further with good AP ratios on her utility. She also becomes a massive lane bully that almost every melee would straight up lose in because of her Q harass and limitless CC and disengage. She would provide a lot of damage and huge utility that couldn't be matched by normal mages.
Before her rework that pretty much made it impossible to solo lane, she would be able to get constant harass with her Q and stacking MR reduction. Her E basically was free damage to anyone in range because of its laughable cost. Assassins had a terrible time vs her because of a 2 second silence and huge armor buff on her heal.
Oppressive champion that would win most extended trades with his Q and W while being full tank and getting a ton of damage thanks to his ultimate passive. He pretty much made any melee top laner unable to beat him.
mid would have by far the best wave clear in the entire game with her Q. It had huge range and can one shot the entire minion wave with one spell while not even being near the minion wave at all. This was a time where baron buff didn't give damage reduction to minions would basically require your team to have a good split pusher or be unable to end the game.

seems to be fine in Solo-Lanes as well as in Bot-Lane. Her stregth gets amplified by Items, her Q deals more damage, but she is balanced in other roles as well as Support. So there should be a way to balance Lulu for both lanes.
actually was fine in solo-Lanes, also as Support, just like Karma - until they decided to take away her only really good Keystone with Thunderlord's no longer being activated by her W only.
is fine in Toplane as well, he was fine in Jungle before and still is good Top & Support
is fine in Mid-Lane as well as Support.
isn't.
Sup >
Sup