Any particular subclass you’re interested in? All are relatively viable. There’s good universal exotics like Transversive and Ophidians, but there’s also some good subclass-specific ones like Astrocyte.
One of my favorite builds, especially 3v3, is Final Warning on Solar Warlock. I run Transversives, but the reload on Icarus Dash exotic would accomplish a similar function. Heat Rises and Icarus Dash for aspects, fragments to your preference. Stat wise, health and grenade with some class for Phoenix dive if you can get it. I run a solar auto rifle with it, but any mid-long range weapon is a good substitute. AE can make landing headshots challenging, so I’d recommend something with body shot forgiveness. Also, look into Icarus Dash skating to get the most of this build. There’s one with burst glide and another with strafe. Strafe is faster, but requires heat rises to be active.
A fun void build is Astrocyte blink warlock with Lemon and your choice of close range weapon. HC shotty or a sidearm are what I prefer (HC shoots for meta, sidearm for fun). Feed the Void for devour and Child of the Old Gods is a good “get off me” tool, but you could also go for HHSN (wouldn’t recommend, but the fling is hilarious). Stats go for high health (health is meta) and melee.
If you want any others let me know. I’m no PvP sweat, but I make a lot of random builds. :)