Like 80% of the top teams use arachna. I'm wondering how to counter her, she's very frustrating to fight against. Right now we're level 60-77. Does Arachna fall off at higher levels? Or is there a good counter hero?

Believe it or not Arachna is even stronger late game because of her awakened ability. The best way to counter her is use strong single target damage and try to drop her before she can use her ult. Heroes like Slim/Garrick/Mortus do particularly well because of this

Serafine,cara,Garrick,gizmo,Slim and Mortus will do just fine with her

is Vincent a good tank to deal with her?
in my server a lot of people are using her with aoe teams...

Cara, Xanos, Dokras, Jasmine. Arachna hits her ult on Dokras' little sonics who die first, which gives enough time for Cara and Jasmine to charge up their ults and finish her off.

Puckersunchers wrote:

Cara, Xanos, Dokras, Jasmine. Arachna hits her ult on Dokras' little sonics who die first, which gives enough time for Cara and Jasmine to charge up their ults and finish her off.

Xanos is not the very best to counter her, but he's good

Anyone with a ranged physical attack like gale, garrick, or bloodspear will take her down fast. You want to take her out as fast as possible without getting poisoned.

Depend if she is a tank or not.
If she is a tank use single target physical heroes. If she is behind a tank use magic team against her. Never use a physical AOE against her.

How beat Archana? Spend money and copy the other team, that's what all the so called 'good' players do lol