Necessary Zyra nerf
I honestly think that Zyra has too little counterplay, despite her rework.
He passive spawn seeds too quickly to for them to be cleared, giving her plenty of ways to deal too much damage in a teamfight, not to mention that, in laning phase, if you try to clear her seeds, she simply uses an ability, winning any trade by default.
So, I think that her passive could be lessened in the early game, spawning much fewer seeds and her E could use the Xerath treatment: if enemies are snared closer, they are snared for less time, since she's a poke mage with good dps she can't also have a good escape. It's about time the mages actually have weaknesses other than "they're squishy, lul".
In return her E could lose the scalling snare duration with ability level and instead be a fixed one, with ability level basically increasing damage and greatly decreasing cooldown.
This would put her in a much better position since between her E and Zhonia's she's pretty much untouchable and with her poke strength (poke with ability and have some extra damage with plant) and dps strength (Rilay's and Liandri's) it makes her too well rounded for a mage.
PS: No, mana costs isn't a downside for a mage when they never run out of mana.