Dyna Stone

These naturally forming stones sit in the Marines' vaults as a jealously guarded trump card. Their intended job was guarding the three Endpoints, and with them the wider New World, against raids by pirates. Since a single one can level so much, private citizens are barred from holding them, and the Marines keep their stock locked behind heavy security. Even so, the stones have slipped into other hands more than once across the stories that feature them.

A regular Dyna Stone runs roughly the size and oval shape of a rugby ball, colored gray with jagged fissures that glow like magma, and it is kept inside a sturdy metal case flooded with tinted liquid so that stray oxygen cannot reach it, since contact with air is what triggers the blast. Each stone matches the Ancient Weapons for sheer scale of ruin, going off much as a nuclear bomb would and able to erase an entire island. They can also be shrunk to grape-sized fragments fitted into tiny canisters that double as arrowheads, breaking open on impact to bare the stone and set off a detonation fierce enough to torch Marine battleships.

Across One Piece Film: Z, the former admiral Z and his Neo Marines rob the stones from Firs Island to power his Grand Reboot plot, wiping out two of the three Endpoints before the Straw Hats and the Marines halt him at the final one; Kuzan afterward freezes what stones remain to stop them detonating. In the Heart of Gold special, Naomi Drunk caps her arrows with miniature stones to sink Marine vessels, only for Zoro to cut them from the air. Within One Piece: World Seeker, the mineral is dug from Jail Island, and the scientist Isaac schemes to smash a stone-loaded sky prison into Mary Geoise before he is convinced to self-destruct it instead.