I have dragon claw on hot key F2 on the left side, and dragon flight on hot key F3 on the right side.
So if your dueling a bone necro, you have shadow master out of course, then...
Hit F2, F3 so both skills are out. Dragon flight to them and click on him with left mouse button. That will rip him apart and you won't get hit.
If he teleports away, re dragon flight, don't run cause the bug only works with dragon flight...