I just killed the syndicate mastermind for the first time. cost me about 40-45% of a level's experience in deaths, but got the job done with 1 portal to spare... Will certainly need better chaos resist for it next time around!
One of the things with reconfigs, often you're going from well leveled gems, and so more powerful spells, to level 1 gems with their basic level. I often shove a thing I want to test out into one of the slots of things I don't use much/at all just to get it up a few levels before actually trying it even