Need help refining a build idea: Voltaxic Rift to make an ARChmage Poisoner

Here's the basic idea:
- Voltaxic Rift converts 60% Lightning Damage to Chaos, which means I can use it to chain poison.
- With Trickster's Noxius, an Agony Herald and two Medium Cluster notables: Septic Strike, Arc gets 100% chance to poison.
- With Archmage basically boosting my Chaos Source, Poison deals a lot of damage. Spell Echo should guarantee two hits (maybe?).

Here are my questions:

1. Am I missing something? It seems that this should work, and PoB seems to agree with me.
2. How should I boost my damage more, without turning into a pure ARChmage?
3. I can't stack multiple small poisons like Blade Vortex, but I should be able to inflict a couple of huge poisons. What else can I do to abuse this effect?
4. Any other tips and tricks to make this build work is greatly appreciated.

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More details:

Offense:
- Arc | Archmage | Arcane Surge | Spell Echo, with no other equipment except Lv20 gems and Voltaxic Rift:
a. Controlled Destruction + Lightning Pen = 29,807 Total DPS inc. Poison
b. Unbound Ailments + Vile Toxins = 31,031 Total DPS inc. Poison
- Herald of Agony + ???
- Plague Bearer? (on a Voideye?)

Defense:
- Stack Evasion Rating on gear
- Acrobatics, Elusive notables (with Trickster's Mistwalker) and a Quartz Flask for 75%/65% Dodge are on the path of the passive tree

ps. why not just make an ARChmage, which seems like an easier and more powerful build?

I think you meant assassin instead of trickster.

It's a great concept to use lightning spells to inflict poison, Arc especially because of its nature of auto-targetting.

However I find it easier to build without Archmage. It's difficult to stack mana (as well as mana regen) and want to go crit and dodge at the same time. You also need high cast rate to stack the poisons.

Dendrobate 6L is cheap on trade now and this chest seems to fit perfectly.

Archmage builds usually go EO and Agnostic as defense instead of dodge.