my mag necro is currently running balorgh + dark convergence + plaguebreak

balorgh would probably be better for a pvp setup, but it works well for helping to burst down large trash mobs (you could easily switch out the monster set for another monster set, or even arena weapons, whichever works best for you, for PVE it might be better to use prior therric from red petal bastion for the increased aoe dmg)

heavy dmg combo is colossus ult, which proc DC and can trigger up to 3 plaguebreaks, then you are doing light attacks into this while it is going to get 1-2 more plagues before the ult finishes, usually final hit on ult kills something which does a plaguebreak reaction which can get up to 30-40k dmg procs if the mob is large enough (most of the time everytime dies before DC even explodes but on tougher enemies you would then get another massive DC proc hitting them)

this build is not the greatest dps for say full on bosses unless they have a lot of adds that you can use to feed both plague and DC scaling dmg (DC scaling dmg will be fixed next update)

my usual sustained dps against a boss is only about 15k dps max, but i can 1 shot 3 mobs with basically 1 ult in a group dungeon pulling them all together lol

edit: i know it sounds like you are using a DK, but this is my use case, you could do something similar on a DK with the standard as that would proc DC too

For stamina stick it on a warden weapons/jewellery and use titanic cleave on the other bar

Assuming you have lotus/netch up (for your major brutality/savagery)

Polar wind, shalks, caltrops (procs DC), swap, cleave (if not all dead)

you can clear trash packs with 200K+ dps numbers.

I'm not sure the other set matters for the DC side of the equation, everything trash is frequently dead before the shalks hit and with the buff in U33 to make DC even more OP for that use style it'll be silly.

I would stack it with a single target focussed set because whilst DC is hilarious it's impact on bosses is a bit minimal. It's easier to control with titanic cleave on one bar and 5 DC on the other but does mean a bar swap for the cleaves.

For pure hilarity however nothing beats DC + mad tinkerer if you can get the timing right.

Monster helm doesn't really matter too much on the trash as it's already dead. Infernal guardian adds to the general mayhem and is procced by the cleave, the usual crit focussed sets are more useful for the boss fights (stormfist etc)

I use DC/trickery on my pvp magdk to farm gear. i use ash cloud to proc dc. it's super cheap.