I find having a bound demon to tank T5 P8 Heralds a great QOL regardless of spec
Even on my current magic es spec I have a 20 soft point stone skin Urdar from Act 4 to help tank Heralds.
Also, you can create TZ games to find a trait that you want for your demon and then shard it to bind a demon with that trait.
I like to find stone skin TZ game and bind an Urdar there, makes them pretty much unkillable.
sounds awesome! i would like to have that extra tank against some nasty heralds.
would you recommend 2 tainted 1 bound demon vs 3 tainted then? they do an awful lot of damage