Well, if u will go to pve lock, its more less same build as pvp. Just change experts. U must have grimo 4/4, it low too much both def, and will help ur entire party. Then, if u go full pve, u have 2 choices. Or max sphere (u will deal pretty dmg if u have many energy amount, but when u spamm skills, sphere gonna suck in dmg, so if u are energy pot user, i recomend) or max relaxation (well, most ppl rhink it sucks. But with this new aggro system, u shdnt get touch constantly, and at boss u will deal more dmg constantly than sphere). If u head to mix lock, go for 4/4 grimo 4/4 new skill, coz it affect to boss, and has nice stun, and if u wil go to stunner lock, hex and new passive (not recomended) this build ia for SUPPORT in arenas. U can make 2 ppl hard to do any skill. Grimo wil help u more to down any character, thx of fero system.
As lock, u should focus in coldown, hp, life steal and crit (in this order) locks dont need much pene since they have grimorie. Locks deals too much dmg by dots, so cd for cast faster and crit and life steal gonna help u to sustain. Take at least 30% coldown, 10-15% life steal +3.5k hp, 2-5% pene enough, 18% crit enough for me, but u can go more, try to get +50 harmony +280 energy
I hope i help u, after work gonna explain which relics u should take so be patient