Ragerune oh rage rune..where art thou?

I'm sure that I am not the only one in this boat but is anyone else having poor luck with rune farming lately?

About to 6* my lushen - yet...no rage lushen runes :(

Probably upwards of 1,000 energy and 1 decent 5* rage rune to show for it.

Am I doing something wrong? :| #opentosuggestions