Venomancer

If the lane is tough, consider putting more points in Plague Wards and move to the jungle if necessary.

Hit opponents regularly to apply ticking damage from Poison Sting.

Galed opponents can be denied, so do your best to secure a last hit on a dying hero.

Deny low health Plague Wards to deprive opponents of extra gold.

Venomancer is great at defending towers as you can place a bunch of Plague Wards around it.

Use Plague Wards off cd when you are moving around to scout, control runes and block camps.

Farm aggressively, as Plague Wards provide vision and farm dangerous spots for you along with gale and sting.

In fights, look to affect as many heroes as possible with Venomous Gale.

When not much is happening, push out the side lanes with Gale and Plague Wards.

Pick up Aghanims Scepter as the game progresses to significantly improve your teamfighting.

Noxious Plague will snowball a teamfight in your favour if you can burst down the first hero affected by it.

Bring extra consumables to the lane against Venomancer's Poison Sting harass.

Cloak has a lot of value against Venomancer's insane magic damage output.

Consider teleporting out quickly when you find yourself in trouble against Venomancer.

Debuff immunity and magic resistance items are great against Venomancer.

Items that provide dispels are able to remove Venomous Gale and Poison Sting.