-----
Since Gestrudo absorbed the Divine Beast Fragment of a Grotesque Aberration that his entire self changed, but it was until he was completely decimated and had his soul eaten when he realized his new capabilities.
Of course, it would not make any freaking sense that he was to be alive if his soul were eaten, right?
Well, it was quite simple, Gestrudo did die.
However, when he was blasted into countless pieces, his soul was also fragmented this way, and although most of his soul fragments were eaten by the Harpy siblings, the tiniest of bits remained within the ground, bind into pieces of flesh that could barely move.
Inferno and Faggoth were completely gone, but the resilient Demon Minotaur remained, somehow.
At first, he felt incredible pain and was even becoming insane, he did not have a normal body anymore, he was but a mass of flesh after all.
Check "The Protagonist's Sister Is Actually the Strongest"!