Tarte's EmphasEYES Clay liner ended up winning! This retails for $22 and comes with a brush. One end is fine tipped and the other is meant for smudging.
Then with my recent MAC haul, I was finally able to compare Tarte and MAC's Fluidline Blacktrack. The differences are that Blacktrack is $15, 0.02oz larger, and does not come with a brush. I wish I had swatched the two before I purchased Blacktrack! Tarte is definitely the underdog with longer wear, smoother application, and opaque (a true true black) with less layers!
Tarte on top, MAC on bottom. Tarte is clearly darker and dries to a matte finish. I built the opacity in 1.5 coats, whereas MAC took over 2.
I have now completed testing all the high end brands I've been curious about. I have also used Wet N Wild and Elf's liners, but they always dry out so quickly on me and definitely do not apply as smooth as the high end brands. Tarte's EmphasEYES is the blackest and longest wearing liner I have come across and highly recommend it! If you're in the market for a new liner, check this out because it will not disappoint!!