Chances are he used your blood to incapacitate Damian.
It should be remembered that a single complete defoliation of a herbaceous annual may so incapacitate the assimilation that no stores are available for seeds, tubers, &c., for another year, or at most so little that feeble plants only come up. In the case of a tree matters run somewhat differently; most large trees in full foliage have far more assimilatory surface than is immediately necessary, and if the injury is confined to a single year it may be a small event in the life of the tree, but if repeated the cambium, bud-stores and fruiting may all suffer.
Sure, a few gunshots may incapacitate zombies, but removing their heads is the best way to go.
That black gunk is lethal, and ought to incapacitate anybody.
If the power of the mind could be harnessed, investigators speculated that it might be possible to incapacitate a foreign leader or even an enemy army.