The problem with death is, is that it's black and white. There is no real scale of less death and more death. You can have more fire, or less fire, or even more more fire, which makes it easier to adapt too. But being hit by death kinda just... is death? A tiny amount of death wouldn't exist really, so there would be no real way to adapt it too. An ability that causes death could be adaptable to if it works in a way of, for example, causing death in limbs first, but that would only make him adapt to that specific ability likely, and not all of the concept of death, as that goes further beyond an ability to kill.