Tiamat

Tiamat (ティアマト, Tiamato) designates a line of thermonuclear cruise missiles built by the United States military, intercontinental in reach, hypersonic in speed, and cutting edge in every respect. Their first use in the field comes against Tomura Shigaraki, in Chapter 331 and Episode 139. The name belongs to the Babylonian goddess of chaos and the primordial sea.

The design follows the archetypal shape of an intercontinental cruise missile adapted to carry advanced thermonuclear weaponry: conspicuously large wings, fin stabilizers, and propulsion strong enough to push it to hypersonic speed. Every unit carries a serial number printed above the wings.

Star and Stripe, the number one Pro Hero in the United States, holds a standing authority to request them from military commander Timothy Agpar. An approved request puts the missiles in the air shortly afterward, and they cover the distance to their destination quickly. She uses them together with the air construct of Fist Bump to the Earth, folding the warheads into a single overwhelming blow, the State-of-the-Art Hypersonic Intercontinental Cruise Punch, thrown with the intent of killing Tomura outright. Agpar makes clear that firing them outside of wartime runs against a stack of national and international law, and that asking for them at all will cost her the hero license.

Cathleen Bate, Star and Stripe, is the one who calls for them and delivers them. Timothy Agpar approves the request on the military's side, and the United States military owns and operates the missiles themselves. Their target is Tomura Shigaraki.