I think that so much of the tragedy in Del Toro's Frankenstein comes from how, in Victorās obsession with death, he shows a startling disregard for life which is what makes his actions all the more monstrous as the story goes on. He never truly sought to create life, but to make a mockery of death. He never considered what would come after giving the Creature life because, despite his aim to restore life, he worshipped only death. So, does it come as any surprise that the Creatureās life should mean so little to him once Victor had "conquered" his death? All this to say that Victor does not respect life because he is, in essence, already dead inside.
In the story of a man and an undead monster, between the two of them, it is Victor, not the Creature, who is the walking corpse, and Guillermo Del Toro couldn't have chosen a more tragic approach to Frankenstein than that if he tried.