Yesterday was a good day where I got most of the Vanguard steps done as well as a bit over half of the kills for Randy. I still have the last step for Vanguard, which is to get arc kills for the Timeless Vigil emblem. Since it's arc I will use my titan to get the 900 kills done quickly, especially since it's grenadier effect in strikes today!
The idea is simple: Use the insurmountable skullfort for unlimited shoulder charge and use Monte Carlo for the moments when you loose your melee. Combine with a 1-2 punch shotgun and thunder coil mod for an amazing damage. Also drop in 5 grenade mods and a fastball mod for insane grenade speed, especially since we go top tree where we get 2 grenades and shoulder charge will almost instantly replenish our grenades.
I think this will be a fun build as I will spam grenades non-stop and I have a decent one shot potential using shotgun and shoulder charge with thunder coil. It will not be as powerful as the fire build using peregrin and hammerstrike, but this should be easier to sustain.
Those 900 kills should be done in no time.