Omg, this took me 4 weeks to get a 150 kills with excella.
I almost give up after my progress got worst.
I was going the other direction, getting s rank (less than 90k points) is discouraging.
Those stupid dogs gave me the most problem.
Finally, with a little luck of some extra freeze rounds, gave me extra time and took out the big man majinis quick.
Finished 150 kills with 1.47 seconds left on the clock.