The whole part where Gabe and Sari are trapped in said mummy's tomb is pretty horrifying. We're not spared the descriptions of how weak they're getting as they start to have trouble breathing.
Anyone that violates the mummy's tomb is punished by being mummified alive, which entails cranial extraction, disembowelment, and boiling tar.
Ahmed is one of the scarier villains because of how understated he is. He seems more or less like a normal guy at first, then the sense that there's something not right with him starts building, and he just gets worse from there.