Her Q functions as harass and wave clear.
She has above average defense stats.
Her instant cast root prevents him from jumping on her pre-6.
Her ult prevents him from jumping on her post-6
let me list 2 problems that are my main argument for why even lissandra has a hard time
1)lisandra pays with mana
2)lissandras ult has longer cooldown(thats hte main issue that zed can play around)
on top of lissandra having equal range with zed's q only when zed intentionaly stands in the creep vave
And her free spells go a long way towards keeping up with his energy costs.
she cant keep up with the spam, if zed conserves his energy its fine
when we speak about mana starving the mages people forget that letting zed push you to tower gives safety but takes away your farm, if you want to get your cs you will drain that ana pool out
And if Lissandra is building assassin (less likely now that DFG is gone): her assassination pattern counters Zed's. Since she's able to deny him his mobility while she kills him.
personaly wouldnt advise it on a short ranged mage whos actual speciality is cc not burst (i dont deny she has burst)
thiis just gives zed an advantage in teamfights since someone else might take lissandra on or force her ult down
also you forget one thing that realy breaks lissandra here
qq's actualy fits zeds build this time, i never saw zed build it, even when i played lissandra vs him but i realy wouldnt like to see it