In the past I've tried Nechro, Oversoul Edict, Fang, and Fatebringer as arc primaries during Arc burns and Rainbow burns. I've even done extra runs those weeks to really test/compare and try to be objective My experience has been ANY of the arc primaries are better than Nechro and that was when Fatebringer was still stuck at 300 Truth be told with all the hive Knights on this strike (Omnigul) Oversoul Edict is a fantastic weapon (seems to be what it was made for) since you can melt boomers while they stop shooting - You can get a similar effect by using Song of Ir Yut instead/in addition to OE note:(I adore FB but killing boomers through wall of darkness makes this strike faster/easier than a few mobs of thrall exploding) I've actually found VOC or Vex to be my go-to primary for this strike on rainbow burn to melt the shanks (Vex still melts mobs of thrall too) and after all shanks gone in last array area, swap back to OE/Fang/FB - with rainbow you can VOC through this Try OE and do an extra run solo just clearing the first room. Last room is amazing when boomer knights literally stop shooting and you can just kill them quick through wall of darkness I'll re-try Nechro after it gets buffed