Janna should be next in line to get an Ezreal-level VGU
In my opinion, Janna needs it more than Ezreal. Legit only 2 of her skins have good looking models (Forecast and Sacred Sword), while the rest look so terrible (toilet paper should not move like that). Her effects also don't do Janna justice; they don't really portray her powers that well.
And like Ezreal, she does have problems/design flaws within her kit but not that bad to make her terrible.
Her Design Flaws
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The 8% movement speed she gives to allies is too subtle and gives too much power without being that noticeable or satisfying.
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The bonus magic damage on her AA's and W, barely noticeable. Only useful on W at mid-game.
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All her poking power was moved to her W, AA's don't feel good enough to use compared to it. When the passive finally starts to get some big numbers, it starts to get too risky to even use them.
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550 range for basic attacking is the general norm for enchanter supports, but it's way too oppressive for a champion like Janna. A big shield and a 0.5 second knockup means enemies can't really retaliate.
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The bonus attack damage on her shield. Doesn't fit thematically. Although useful, hard to know it's there. Also only get full effect on crit ADC's or Yi, but near useless on anything else; should be more general.
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Her W being a viable poke ability in the first place, literally just right-clicking people for 250 damage isn't the most exciting.
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Her ultimate has a heal, but it's not really used for the heal. It's more of a cockblock-ability than a push-enemies-away-and-revitalize-your-teammates-ability.
Please let Janna be the next VGU, she's been waiting for a very long time.

, I think Riot will come to a point when they will rework EVERY champions to the ground.
Cough