How do I counter Lissandra?
I don't know how to beat her. She is so damn annoying to play against. What are some tips to fight her?
I don't know how to beat her. She is so damn annoying to play against. What are some tips to fight her?

Wear mittens, A warm Jacket, Toque and some hot chocolate.
the best way to counter lissandra is to go high ranged champions force her to use ult on herself just because she can heal doesn't mean thats the best thing for her to do. keep moving dont bother to hide behind your minions she has the shortest spell range of any mage buy
late game so that if she tries to engage with her ult on you it won't work.
I sorta main Lissandra and I have to say that certain champs are really hard against her. Fizz is tough on her, Ahri, high mobility champs like that. Alternatively, you could build Zhonyas, Merc treads, shit like that and cut down on her CC.
Don't stand behind your minions, her Q does a cone splash on what it hits.
Top or mid?
Top she's a bitch if you're a melee champion. Not much you can do, build magic resist and hope for the best.
Mid you should be able to outpoke her, since she is a short range mage.
What the above said, and also QSS is a great item for AD champions going against her, perhaps a Banshee's Veil, too.