the Warlock

A warlock must make a lot of damages and do this so fast because he have low defense and it is easy to knock him down. use fast staff!
in 1vs1 warlock will try to make dizzy effect (he can with meteor at 30m, with silence at 25m, with master of doom at 15m). Lighting and fireball are powerful power, i like very much Vampirism and soulkeeper that drain helath from enemies, and energy borrow allow you to drain mana.
his weak points are low defence and speed... a cojurer have the way to defence/heal himself so never mind if he has a low speed. in 1vs1 is useless run away cause the other capture you, so don't run away but try to fight! the big problem is the defence, warlocks don't have defensive spell, we have only energy barrier and wind wall.

in a pvp if you are a warlock:

vs a warlock: make dizzy effect before he make it on you. then block spell, and at the end spell that make damages.

vs a barbarian: alternate block spell and spell that make damages. he arrive at you as soon as you think, so slow him down and make him damages.

vs a knight: it is very hard win with them, don't use spell that have a low cooldown cause the knight is fast and he evade your spell and attack you. Try the twister and the ivy so you can stop him!

vs a hunter: if you are not ready maybe you lose the battle. he can use his pet against you or cast SOTW. under sowt effect don't cast spell...
as soon as possible make he dizzy and drain life from him with soulkeeper and vampirism.

vs a marksman: as the hunter, with the difference that he haven't a pet but he can make a lot of damages... so if i cast on you Sotw you are die!!

vs a conjurer: if he has a creature summoned steal it! or you are die! The first who make the opponent dizzy can win!

only tactict for warlock: kill them before that they kill you! fast! as soon as possible!