Final boss invincible ?

[Bacup]

I've hit this boss (in its last phase) about 90 times with a metal bar (I've count) and he's not dying, he keep fighting back
How am I suppose to kill him ???

I've searched on the net about a bug like that but found nothing
Anyone can help ?

[Faded]

Maybe you are interrupting his animation with so many hits

[A-Nukem]

You can stun lock him with the axe, just hit him non stop and he can't block.
At one point he'll seem somewhat weakened - wait for the message to press "1" to remove the face metal (he doesn't fall down on his knees in the last phase).