I use a MagDK bomb build in Group play—it's in no way Ideal, and is outperformed by a Magblade bomber every time due to Magblade ulti regen, Damage and Sustain. However it is at least some damage, and in some cases decent CC.

I use 5x Spinner 5x VD 2x BloodSpawn. DW not S&B—never use S&B if you try this. And make sure you have a Decisive staff on your back bar—it's so important.

Front bar: Whip, Talons, Inner light, Empowering Chains, Deep Breathe & Leap.
Back bar: Balance, Moltan Armaments, Mist form, Proxy, Harness & Destro Ulti.

Essentially you're going to have your Destro ulti every other push—so it's important to know when to Leap the stack and when to save ulti. Leap can be used as a sort of Pseudo Negate, and is probably the best thing about the class in group play—although that's not saying much at all. If they're spread out, and you're pushing an open field (Such as when you're pushing out of a resource) it's best to destro ulti and roll it with your group. If you're turning and hitting a thick stack of 12-20 players the CC from Leap timed with other destros can be almost as good as a Negate. When you're rolling Destro ulti you want to Spam talons mostly. Alternate between two casts of Talons to every one cast of Deep Breathe.

Overall, the build works—I mean, in the sense that Damage happens, VD procs and people die. But it will not work solo, you absolutely have to have a group for this to be viable unlike NBs which have the damage to solo bomb—DK does not. I wouldn't recommenced rolling DK to play this build, as it's mostly detrimental to your group to have this instead of a Magblade bomber. It is a decent option if you're a DK main who's trying to grind out the last couple star ranks. Using this build I've went from One Star to Four Star over the course of double AP.