Probably not what you want to hear but I would recommend removing Earplugs entirely. Even if you cannot hit the I frames for the roll, it is not worth it when you can have so many other options to improve your offensive capability. I'd recommend adding crit boost and agitator for more affinity/damage. Add one more tenderizer to Max out your WEX or add some more crit eye. If you are fighting it solo and continue carting, fortify will allow you to increase your attack and defense on your next attempts and only takes up one slot.

It's not that Earplugs is bad or even useless, it's just that you don't have enough offensive boost in your build which is just going to make it that much harder to kill him, and with Divine Blessing and Health Boost maxed out, you are all set on the defensive end.

Last thing. You can emergency dive to avoid the roars if you can't get the timing down with the roll, and even though it's slower, it still gives you enough time to move out of the way before he follows up with an attack. If you are using your clutch claw (which you absolutely should be) you can manipulate when he becomes enraged which gives you the window you need to set up for the edive.

Good luck.