This build is super simple.
Food for Orc or Dark Elf: Artaeum Takeaway Broth
Food for Wood Elf: Bewitched Sugar Skulls
Rotation: Keep “Inspired Scholarship," “Quick Cloak,” and “Structured Entropy” up, then flail, flail, beam, flail, fail, beam all day long. Use your ultimate when you want some extra burst damage or when it is available.
For soloing DLC dungeons, swap out “Structured Entropy” for any of these flex skills: Runeguard of Freedom, Evolving Runemend, Runic Embrace, Runic Sunder, Cruxweaver Armor. For really spicy fights, swap out “Cephaliarch's Flail” for Evolving Runemend, and then swap “Structured Entropy” for another one of the named flex skills.
For the Trifecta group DPS setup, the key is to use the ultimate and fulminating rune as flex spots to support your group and make your strategy work. If you need to provide some extra support in the form of a Barrier, which is best cast by an arcanist (this build can cast a 52k barrier) then do it. If your group needs insane sustained burst healing (like the lightning bear or the lightning strikes in Earthen Root Enclave), swap out your Fulminating Rune for Cascading Fortune which can heal through both of those on this build with ease, taking a little pressure off of your healer in the process. DPSing in a group can be either super rigid “everyone do their roles perfectly” or there can be “we get the job done no matter what it takes.” I prefer the later with some flexibility, and this build does that well.
Also for the Trifecta DPS, that Kvatch Gladiator set is not strictly necessary for every fight. There may be much better sets for some dungeons. However, in Earthen Root Enclave where this build cut its teeth, that extra execute damage was super important in all three boss fights.