Your character committed suicide

A warning post.

Mana flask that removes 15% life when used can kill you.

Popular Monk build. Chaos Inoculation lowers your HP to 1 (one) and Eternal Youth allows to use life flask to restore energy shield. Using mana flask that removes part of your life works fine in this setup, but as soon as you deactivate Eternal Youth it will kill you instantly.

Usually you disable Eternal Youth when you want to use Faith is Choice for Meditation skill.

The mana flask uses your max HP before CI for calculation. Odd when in the same time skills, that benefit from being on low life, don't apply when using CI.

It is not a common knowledge, maybe it will save you.

LVL 86 hardcore monk RIP.