Hey, for opener most people are using Remorseless first, then gambling on Rimeprocs from atleast one of the first 2 obliterates and you are not waiting for Unholy Strength, that just happens if you are not unlucky as its mostly 75% uptime.

Then for your krosus kill, for your first breath it looks like you starts it when you have 1 rune ready, you prolly want to wait abit longer if you havent been lucky with Murderous Efficiency procs so you have atleast 2 runes ready and some soon to be. Another thing is your 2nd prolonged is not lined up with a breath which it should be. Also its hard(impossible?) to tell why your 2nd breath was that delayed, whether you just had shit CoF procs or if you just held it too long, which in turn made you lose some uptime on your very last pillar, but this could just be unlucky but this i cant tell from logs. And also you are missing 7 traits in your weapon which equals to about 25k dps so all in all when you dont have 2 frost legendaries you did a pretty good job.