Omega for Sidious leader ability

Alright so by no means is this official and I only did 2 rest runs and backed out, but this was the damage of Sidious first attack was 4744 and by the end it was critting around 6056. The numbers could actually be much higher, no crit set, no crit triangle, only level 80 blah blah. I have him just shy of 200 speed I believe so I'll just estimate and say I hit with his basic 30 times. I kept track as I went along too and it gradually was going up, so I'm going to say it is indeed a stacking 2%. But alas, someone with more proper testing can straighten it out one way or the other.

First attack on Captain: 4774
Last attack before Sidious would've died at enrage: 6056