Feats, i have 2 builds i like, one Conflag one Havoc.
Havoc (Current):
http://www.conanarmory.com/feat.aspx?id ... f2e2def5ef Havoc: Having levelled up pretty much 2 Charcters solo i always chose a more solo oriented build, and havoc was great for this, a wide range of CC with a few tricks to throw out if you get in trouble, relies on Rooting and moving, staying behind your target so they dont get the chance to do too much dmg, great build for 1-80 but falls short past 80 and into the mass pvp game. The one defining skill of Havoc, well 2, are the Knockbacks, but with greater and greater resistance to it in the tier 1 sets it becomes less and less reliable and so the switch to Conflag.
Conflag (what im most likely switching to) :
http://www.conanarmory.com/feat.aspx?bu ... 2def5ef:33 Conflag: This is what i call my "Stealth" Demo build, relies very heavily on getting off the first attack in that it reduces the ammount of CC you have at your disposal (no 2 knockbacks) only 1 stun, 2 roots. but its all you need. Played around with the fire spec a little and while ther are some novalty feats (impish Horde) it still holds alot of utility (buffing grp for more dmg) and the IWIN spell for Demonologists "Greater Flames". Combined with the "hit this target" spell Gate of Hell, which can be used as a focus target for raid/pvp situations due to its obvious graphic.
Archamage Talent used in both specs to up the dmg of the off-spec aoe, it is possible to "chain" both AoEs, but not reliably so having the 2nd do top dmg is priority, obviously doesnt matter for PvP but its nice to have both AoEs usable in PvE.
I think the best role for Demo in pvp is not up front, because we simply dont last long enough when there are melee/ToS around. Its between the healers and melee, so were not in the direct firing line, but we are enough of a concern to draw attention away from healers. from messing around on ETs Battlekeep i think our best place by far is gate defense, 3 or 4 demos with one healer atop the gate is insane dmg for anyone attacking the gate, activate Pact and Tome and unleash the AoE whilst being out of line of sight, with the added bonus if you decide to spellweave your AoE should be hitting for 1k on each target if not more.
Can be contacted in game on my alt Onarr.