It’s a nice retal build and no doubt about it. The durability from Bulwark and Healing Rain is great.
Beranoth is huge and allows for almost complete flexibility on items. And not only for BWC rta retal and associated conversions via skills/equipment/devotions, but for all normal retaliations including counterstrike and basic retaliation. (As MLee mentioned). Armor is the main nemesis of small numbers - but once you get past the threshold, few mobs have very significant resists (some boss exceptions). And even with very high enemy armor, 30% gets through before the threshold, which can add up when stacked.
Beranoth [purely imho] is the most insane conversion item out there (100% to many types).
If you were curious to compare a similar concept but different damage type, I did theorize a gimmicky chaos BWC spammer , which is pretty restricted to one conversion. I have no plans to test it, though. And it has not soldier for CS, which means that it would not be a direct comparision.