League of Legends (LoL) Question: Varus right now ?

He's a solid mid laner and a passable ADC. Most common mid. If you know your matchups well, he can be a good pick in poke/siege compositions and he can help engage. Not a priority pick but I'd still consider him a solid meta pick.

Build:

You generally get more armor pen / AD items (like Maw of Malmortius, Mortal Reminder/ Lord Dominik's Regards, maybe Duskblade of Draktharr, sometimes Bloodthirster) and maybe a defensive one like Guardian Angel or Mercurial Scimitar, but that depends on comps and such.

Summoners for mid are Flash + a defensive summoner like Cleanse, Heal, Barrier or Exhaust. Teleport is probably okay as well but not as standard.

I wouldn't take him top. He has no escapes and is a sitting duck for ganks. Mid lane is a lot safer since he can push to tower more quickly and he has the range to poke and farm while staying pretty close to his tower.