Warning: Spoilers for Dark Knights of Steel #8 ahead!Kryptonians like Superman are known for their nigh invulnerability and incredible physical resilience, but a terrifying moment involving Supergirl in the recent Dark Knights of Steel #8 provides a shocking reminder that even those from Krypton are not invincible.

While Dark Knights of Steel takes place in a vastly alternate reality — a medieval style universe where Superman and his parents landed on Earth and become rulers of a powerful kingdom — the powers, strengths, and weaknesses of the members of the House of El are identical to a Kryptonian's mainstream abilities. In DC's mainstream universe heroes like Superman and Supergirl are incredibly hard to kill or even injure, and typically the only way to weaken and harm a Kryptonian is to expose them to radiation from a red sun or put Green Kryptonite near them. However, Dark Knights of Steel shows one other brutal...