This is an amusing idea for an alternate myth of Achilles. What if instead of holding him by the heel, Thetis submerges him fully. Achilles is then completely invulnerable and Thetis has one invulnerable hand. According to the original Greek myth, Achilles was dipped into the River Styx by his mother, Thetis, to make him invulnerable. However, she held him by his heel, leaving that part of his body untouched and thus susceptible to harm. In the Trojan War, Achilles met his demise when Paris, guided by Apollo, shot an arrow into his vulnerable heel, leading to his death.
