Warpath really could use a skill which helps with bosses. I like Sigils of hope, but they are not vialbe against bosses due to mana cost and indirect castubg not working because there are almost never sufficient adds. So SOH only improves our clean speed which I say is already fine.
Healing hands does not help either, because selfcast would never work with 1.5 seconds cast time and only three seconds buff up time. Indirect castsing does not work with warpath so all we could do is forego warepath against bosses and spam Smite, which I highly suspect would not work either.
The mana cost of Sigils of Hope is negated by using Volatile Reversal after casting 4 Sigils.
During boss fights this may have to be done more than once, due to them not replenishing on kills.
We also use Anomaly on Boss fights, to slow them & shred Void Resistance.