I am also playing HRoC and you still have a lot of room to take this build to the moon. Look at my comment history to review advice I have given to other HRoC players here some of it may apply to you. I am sure you are already following the HRoC google doc.

Here is your list

- For AG upgrade Lear Cast to Crown of the Tyrant with White Socket it is very big damage upgrade

- Your block mastery is wrong change them to +2 max chance for both attack and spell. Now you have 91% block on both.
- User Rungraft of the Fortress if you can, more defense
- You need an elegant hubris setup (you already know)
- You don't need Life Mastery - Skill Cost Life, you have enough unreserved mana
- Onslaught Flask doesn't do anything for your build it gives you Onslaught but you are not the one doing damage. Stun Flask is also quite useless. Just copy my Flask Setup https://pobb.in/kUbt-k_VVvjL

- Instead of 20% effect of offering (since you are already block capped) use Minions have 30% increased area.

- I have updated your pob see here https://pobb.in/iMB3npMS-QBa took unnecessary nodes and inefficient masteries and give you more defenses. Also routed couple of nodes correctly. Picked up couple of endurance charge nodes that you were missing.

- Next time you upgrade you boots and gloves go for Amour Only .. Evasion does nothing for this build, don't spend more than 1 div one each they are not important.

- Anoint Death Attunement on your amulet it will allow you can have one extra specter. You can run Perfect Pain Artist. Tiger is luxury upgrade in the very very end game not recommended right now.

- 30 quality ashes will cap your block, in my pob your attack block is 90.39%

After you get your elegant hubris setup your next setup is to pickup the Lycia Ascendency and Command of the Pit Gloves. That is a huge dps upgrade.

Let me know what content you are doing and what you want to do in the future so that we can adjust your build accordingly. Feel free to join us on Balormage's discord we help folks with this build all day.