Blood of the Warrior is bugged and is not being considered a life flask during its duration.

Blood of the Warrior
Gargantuan Life Flask

You get the effects of the flask but gear and nodes that modify the flask do not work

Tested with node Tukohama's Brew which causes "50% of Skill Mana costs Converted to Life Costs during any Life Flask Effect" and does not change skill tooltip cost to life during duration.

This also affects Umbilicus Immortalis "Your Life Flask also applies to your Minions
Minions cannot Die while affected by a Life Flask
(20-30)% increased Flask Charges gained
Tested and minions die during duration do not know if they were getting rage

Thanks for the info.
I was about to try the Umbilicus Immortalis setup. Hope It's a bug and not an intended interaction.

HI i can confirm this bug, would help my build alot if this bug doesnt happen :D