Zyra's Passive
Why not give her something additional? Some champions have passives that have a few benefits to them. Instead of just having the dying true damage, add something to it. Maybe add something like pheromones, where if she damages an enemy with her q e or ulti they get some sort of debuff.
on the radius of her passive plant form. It's a extreemly mirror buff since mostly when she dies she has plants up that slows the enemy anyway but this way she can still hit her passive when she get picked off & her adc now has a chance to kit arround her plant form.