I solo'd it on the omnigul strike a few weeks ago. Having the invis perks for blade dancer helps a lot. Hang out in the first room at the top of the stairs with arc on murmur, then pop out and get one kill before running back to the stairwell. Once the shanks pop run all the way down to the first level and switch to solar. After you kill the shanks, the stealth vandals are going to pop. They will one hit KO you so use a heavy machine gun or rocket launcher on them. After they are down the thrall will start spawning. This is a great chance to rack up kills with a fusion rifle. If you do all of this you should be able to knock out 40-50 fusion kills per run. Repeat until you have your 200.