Its not damage reduction, its defence increase.
If hero have 1000 defence and will get +94% defence against holy this hero will have 1940 defence against holy.
EDIT
If you want know how to calculate damage you can find formula here:
Its not damage reduction, its defence increase.
If hero have 1000 defence and will get +94% defence against holy this hero will have 1940 defence against holy.
EDIT
If you want know how to calculate damage you can find formula here: