This question contains spoilers:
In Dracula Untold, the Sultan creates an entire room filled to the brim with silver to protect himself from Dracula, so clearly he had some way to find out about Vlad's vulnerability.
Why doesn't he have even one cross to protect himself? For that matter, why didn't he equip his entire army with crosses just in case? (just by random chance you'd think at least a few of them would happen to be carrying crosses) Is a cross only effective when wielded by a "holy" person (such as a monk)?