I've played against TF, Fiddlesticks, Gragas, Ahri, and Ziggs mid since I started playing Zilean again
Fid was the only issue cuz he could heal so much so consistently and did a lot of damage when i had to sit in drain cuz of fear
everybody else i could dodge most of their harass or pick up a fw potions and poke back because honestly Zilean's bombs have some of the highest non-ult base damage in the game, and you can cast two in .5 seconds.
Always fun to ult under tower and get a kill+full health, too
Nautilus fed that Ziggs doublebuffs at level 4 and then again when Ziggs' blue buff ran out but I still won trades as long as I could dodge his Q (which isn't hard as Zilean) cuz even with 70 ap I've got enough base damage to shit on squishies and ult the Vayne