Is the -MaxHP portion of Brine supposed to stack?

[brass_eagle]

I was playing around on my Defender and noticed the -MaxHp portion was stacking. I was able to get 4 applications of it on one enemy. City of Data lists it as "Stacking Per Caster".

 

Here are three screenshots from the same enemy:

 

 

 

[Uun]

Working as intended.

 

[Glacier Peak]

Yes, it's supposed to stack. It's awesome.