Bounty of Figarland Shamrock – credible but non-canon

Shamrock is Shanks's twin brother — not some other character's, specifically his, both of them sons of Figarland Garling. One gave up his World Noble rank to become a pirate Emperor; the other kept the name, the sword, and the command of the God's Knights their father left vacant on becoming an Elder. Shamrock doesn't hide his contempt for that choice — in his eyes, Shanks lowered himself into a world he considers filthy.

His weapon, Cerberus, isn't a Devil Fruit at all but a blade that transforms into a three-headed creature, each head spitting its own swords — a capability his swordsmanship and Haki alone are enough to carry, no Zoan or Paramecia required anywhere. In chapter 1138, in the Hells of Elbaf, he wounds Loki with a single strike deep enough that the scene leaves real doubt about survival, then offers him a place among the Knights instead of letting him keep defending the giants.

No organization has ever published a figure on him: not the Marine, which lists him no more than it lists his father, and not Cross Guild, whose entire rating logic stops at the visible officers of the pirate-Marine war and clearly has no idea what to do with a commander who never presented himself as an opponent in that fight at all. The duel this story keeps building toward, between the two brothers, has so far only happened as open contempt — never yet with a blade.