Also, if you use a barrel to kill an enemy, it also counts as a skill. My guess is they programmed it to be any non-buildable and non-primary/secondary attacks count as skills
Since ISIS’s charged cannon counts as skill damage, I wonder if killing the Bonecrusher (or any other skill-related objective) with it counts as a skill kill? Unfortunately, Whiskey’s ult does not.
I found it easy enough with Whiskey, though the 10 minions in 30 seconds challenge didn’t go too well.
I noticed too that on the first op that killing the pylons and snipers with Injection counted as a melee kill, strange things. I’m sure here are other oddities that we don’t know about yet.