I think a majorly overlooked build for warlocks in pvp is soul link succubus. The build is 5 afflic for corruption, 31 demon for soul link and 11 destro for shadow burn. The rest of the points are free.
Soul Link is straight up busted, it reads you take 30% less damage from all sources the rest of the text hardly matters.
The only problem is that the traditional soul link build deals no damage and has no kill potential, other than dice rolling a nightfall.
By using succubus with master demon you get 10% bonus damage from both schools of magic and then an extra 3% from soul link. Combined with shadowburn, this means that the rotation of corruption + pet attack, curse of agony, immolate, shadowburn almost always kills the enemy.
not only is your damage deadly, but seduce + fear can disable 2 player at once, seduce effectly has over 100 yard range and can be cast on targets that are los. You are tanky enough to sit a wotf and seduce after.
It’s a massively powerful build that is both tanky and has burst and good rot. I would say the only weakness is you can’t pick up either bonus range talent.
Ps. Spell stone is the best least use spell in the game, easily swings encounters in your favor, purges silences, novas, you name it.