I don't understand why the last boss in Sekhem killed me

I don't understand why the last boss in Sekhem killed me

Video:

https://www.youtube.com/watch?v=i1DrdFQ9TTU

What did I do wrong?


Why did I die, I collected all the hourglasses?


Has anyone encountered similar behavior from a boss?

It's a bug, when he spawns that hourglass bs back to back, just leave and try again because it's an insta-kill otherwise.

the boss does certain things at certain hp lvls. if u push his hp to fast u can bug it and get 2 of the hourglass rounds at once.
there are tons of videos and guides explaining this out there. once u close to the first hourglass spawn, slow down with dmg and let it play out.
burst again once that phase is done.

Thanks to everyone who wrote in this topic, I realized what I need to do so that he stops killing me.