Idiom used to express something that brings about one's destruction in a very precise and effective way? [closed]

From the point of view of the werewolf, the silver bullet is far from having a positive connotation. What similarly idiomatic word or expression could be used to express something that brings about one's destruction in a very precise and effective –sort of perfect-storm– kind of way?

The context is a promising technology or product that failed due to unrelated and unexpected conditions and/or developments in the market (here there is no fault on the part of the market-player; it's just mere chance). I can imagine this extending perhaps to literary evil characters which had contrived a very clever way to become strong or invincible, but the archetypal weaker character exploits a weakness that the villain did not consider (here there is perhaps some fault/blame to be assigned).

Thanks in advance.

Solution 1:

The fictional mineral "kryptonite" is defined by oxforddictionaries.com as

(in science fiction) an alien mineral with the property of depriving Superman of his powers

This word is often used in popular culture to refer to a singular weakness exhibited by an otherwise competent, or even hyper-competent, individual.

Solution 2:

Consider an "Achilles heel."

noun

1. a portion, spot, area, or the like, that is especially or solely vulnerable:

His Achilles heel is his quick temper.

Solution 3:

The literary term is a tragic flaw.

Tragic flaw is a literary device that can be defined as a trait in a character leading to his downfall and the character is often the hero of the literary piece. This trait could be the lack of self-knowledge, lack of judgment and often it is hubris (pride).

The Greek word for Tragic flaw is hamaratia or hamartanein that means “to err”. It was Aristotle who introduced this term first in his book the Poetics and his idea was that it is an “error of judgment” on the part of a hero that brings his downfall. A tragic flaw is also called a fatal flaw in literature and films. This is taken as a defective trait in the character of the hero.

While the silver bullet is often thought of as the perfect weapon to wield against a strong person, the tragic flaw is something within that person.

-- Edit "fatal flaw" ---

As HotLicks and C.M Weimer pointed out in comments, fatal flaw is in wider use. A quick-and-dirty Google Ngram shows fatal flaw with around three times the frequency of tragic flaw (although they came remarkably close in 1950).