1. Bring scout rifle, any will do (not needed but I seem to hold the trigger to long and screw things up) 2. Head to Vex/Cabal skirmish on Mars, down the hill and to the left of drop in point. 3. Damage them with primary to 15% or so, then finish off with Fusion Rifle. The Cabal and Vex in this area have a bad, (for them, good for Guardian) habit of grouping together when damaged. I have tried other spots like shanks on earth but the spawn rate is slow, if I am in the divide already for 10 Fallen ultra's I will grab it there but this is my goto spot lately. Try it out maybe it will work for you.