Ok, so the scales of ettera say:
Casting a fire spell grants Fire Infusion, with a 20 second cooldown
Fire Infusion gains a stack every second. Each stack grants 8% more fire damage and 6% less cold and lightning damage for 10 seconds. Reaching 10 stacks of Fire Infusion applies Fire Overload for 10 seconds, granting 80% less fire damage and removing all Fire Infusion and Cold or Lightning Overloads
Casting a lightning spell grants Lightning Infusion, with a 20 second cooldown
Lightning Infusion gains a stack every second. Each stack grants 8% more lightning damage and 6% less cold and fire damage for 10 seconds. Reaching 10 stacks of Lightning Infusion applies Lightning Overload for 10 seconds, granting 80% less lightning damage and removing all Lightning Infusion and Cold or Fire Overloads
This does mean, like Unleashed_666 said, that you gain most from this catalyst by using a skill for 10 seconds and then switching to the other one, which should trigger the infusion of the other element, unless they share a global cooldown, which would suck.
The passives Dragon Mage and dragon breath would have you cycle between 3 elements every 4 seconds, to work best.
I was hoping that both could synergize with one another but, I don’t see it happening. There might be some hope for one of the two to work properly for a solid build based on using 2 skills of different elements but, not like what I thought. Thanks for the replies so far.
Nerdherdv02: Maybe using hard-hitting, slower casting spells could help. I had something in mind using volcanic orb and static orb however, this might still not work it you need to stay on one for 10 seconds.
I am level 85 with my mage now but, work is starting again for me this week. I’ll soon be able to afford to swap things around and try different setups.