Conflux will apply the ailment (of that Conflux: e.g. Igniting Conflux apply ignite and so on; Elemental Conflux applies ignite, chill, and shock) based on the total damage of all combined damage types on hit.
For example, when the player with Igniting Conflux deals a hit with the following damage types:
200 Physical
50 Fire
100 Cold
150 Chaos
that hit will apply ignite with damage based on a 500 damage initial hit.
Variants
Igniting Conflux: causes all damage types to apply ignite.
Chilling Conflux: causes all damage types to apply chill.
Shocking Conflux: causes all damage types to apply shock.
Elemental Conflux: combines all three Conflux effects into one and applies ignite, chill, and shock on hit. Note that freeze is not applied by Elemental Conflux.
Scorching Conflux: causes all damage types to apply scorch.
Brittle Conflux: causes all damage types to inflict brittle.
Sapping Conflux: causes all damage types to apply sap.