I'm not much help with Demons but I have some experience with Poison. Take a look at my thugs/poison build here... it may help you a little bit.
Do you have any specific questions in mind for a demon/poison build?
Sounds like it would be a fun and thematic combination. I'd expect great damage with stacking debuffs from you (poison and whip attacks) and your pets. Survivability would probably be middle of the road. I'd definitely do some hefty frankenslotting in the lieuts to make the most out of the resist shield and the ember demon's healing.
I think the first page has a thread or two related to demon poison going on. I would take a look at those and see if they answer any of your questions.
Just remember you cannot created a concept build without sacrificing. Of course unless the ideal powers just happen to be in your build.
The big issue with Poison across all the Arch Types its very single and lacking. I was just looking to do a poison toon on another AT and I went back about 1 year with the searches. I just did not read anything good unfortunately.
1. Why Soft Cap is Important : http://dechskaison.blogspot.com/2011...important.html
2. Limits: http://paragonwiki.com/wiki/Limits
3. Attack Mechanics: http://wiki.cohtitan.com/wiki/Attack_Mechanics
4. Rule of Five: http://wiki.cohtitan.com/wiki/Rule_o...e_Law_of_Fives
Demon/poison is "King" of ST Debuff. Every Debuff you can think of is there, -Regen -Heal, -Reco, Slow, -ToHit, -Dmg, etc.
I love my Demon/Poison it can kill most AVs(did the mender TF for villains to test) but sadly no GMs.
So its not overpowered but its not weak. It has a Small(8') AoE that's half the effect. Solo'd mine from 1-50 in about a month on 0/1/wBoss/wAV.
It has 2 Debuffs by Lv4 so you can debuff right away.
The way to play depends somewhat. For AVs try to start out with Weaken. For Mobs Neuro Breath.
The heal can be "skipped" for slotting since you have to take it, unless you want set bonus. Picking up at least the Cone Whip will help greatly for AoE Dmg.
A Poison can easily Debuff.
Due to all the Debuffs it dose it stacks up to be like any other set if not (a tad) better.
-Regen -Res -Heal(Self heals and outside) -Def, all add up to keep AV down.
Following info is from my dealings and ParagonWiki: http://paragonwiki.com/wiki/Poison
Envenom Lv2 Ranged (Targeted Area of Effect), Foe -DEF(All), -Res(All), -Regen, -Heal
Weaken Lv4 Ranged (Targeted Area of Effect), Foe -DMG, -To-Hit, -Special*
Neurotoxic Breath Lv10 Ranged (Cone), Foe Hold, -Recharge, -SPD
Elixir of Life** Lv16 Close, Ally Rez, +Res(Toxic), +DMG, +To-Hit, +Recharge, +Recovery
Poison Trap Lv35 Place Trap: PBAoE, Foe Hold, -Endurance, -Recovery, Chance to Hold, Minor Damage over Time (Toxic)
Noxious Gas*** Lv38 Infect Henchman: PBAoE, Foe Hold, -DEF(All), -Res(All), -DMG, -To-Hit
*Control Effects and Debuff Effects.
**Elixir: Fun power since it has a 1000Mag Hold for about 3-4s.
***Noxious Gas
You can infect one of your Henchmen, surrounding him with a Noxious Gas. All foes near the infected Henchman will be overcome with the Noxious Gas. Their Defense, chance to hit, Damage, and Damage resistance will all be reduced. Additionally, there is a chance that any affected humanoid enemy will become violently ill. Even the mightiest foe will stop dead in their tracks, and left helpless as he empties the contents of his stomach.
The vomiting Hold effect is rare (less than a 1% chance of occurring per half-second), unaffected by Enhancements and buffs, and applies only to human critters and to other players in PvP, but it has enough magnitude to surpass any protection in the game and is unaffected by status resistances and PvP mez suppression.
The debuff values vary depending on the tier of henchmen the power is used on; the debuffs seem to be at 75% strength on a tier 1 pet, 100% strength on a tier 2 pet, and 125% strength on a tier 3 pet.
Going to miss the fun and nice people here at CoH. Feel free to add me on PS3/XBox360
PS3X360: OmniNogard
Currently playing: Mass Effect 3(PS3) Minecraft(X360) Skyrim(X360).
I haven't seen much in the way of guides or help for this combo. Anyone have any advice? I feel it could be nice and I have character idea behind it.