威国 — Ikoku (“Mighty Nation”; VIZ “Ikoku Sovereignty”) — Big Mom’s signature attack (Ch. 874): she swings Napoleon in longsword form to throw a destroying shockwave, captioned the “Spear of Elbaf” (エルバフの槍 Erubafu no Yari). 威 (i) = “might / awe / intimidation”; 国 (koku) = “nation.”
VIZ renders the shared ending -国 (-koku, “nation”) as “Sovereignty.” Crucially, 威国 Ikoku is also the name of Dorry’s solo variant of Hakoku — so Big Mom’s technique matches the giants’ single-warrior form by exact name. This sharpens (not weakens) the seed: her combat vocabulary is literal Elbaf giant-warrior canon, and Luffy’s “the attack the giants used!!” recognizes a genuine same-name, same-lineage strike.
(Contrast: Big Mom’s sibling strike “Ikoku Sovereignty” (Ch. 874 pp. 5–6) is the same Spear-of-Elbaf family but a horizontal shockwave sweep, not the tunnel-to-vanishing-point composition — same lineage, different framing; it is the name seed, not the visual mirror.)
The payoff
Why this matters
First named technique for the two giants and first named Elbaf weapon-form. Canonizes
giant-tier combat-power as near-absolute and installs the Elbaf giant-warrior weapon
lineage. The paired-strike grammar (two warriors, one combined attack) is the
friendship-restored payoff of the Little Garden arc — the duel-pair fight together
once their hundred-year duel is resolved. Pre-loads the forward-canon Elbaf-arc
giant-combat canon.