RF + poison

when i use RF(Righteous Fire) and The Consuming Dark..do i still apply poison, even righteous fire is debuff

no, for two reasons:

1) Poison requires a Hit. RF doesn't Hit
2) Damage over Time currently cannot be converted. So you'd be dealing no chaos damage

basically, it doesn't work, because RF is degen

Poison is applied on hits. RF is a degeneration effect. Degeneration effects do not hit.

Therefore the answer is no, it will not apply poison for that reason.

Also degeneration effects like RF can never be converted to another damage type.
If you use consuming dark with RF, RF will still be 100% fire damage. Another reason why poison from Consuming Dark will not work with RF.

TL;DR: No

No. Righteous Fire is damage over time. The conversion won't happen, nor the poison.

how ever since RF does not hit this also means you dont have to worry about reflect of any sorts from mobs. and having the higher max fire res will make atziri a little easier, also what kinda of RF build are you doing, max life? :)