Indigo

Indigo is eccentric, theatrical, and highly expressive. His unusual footwear produces comedic noises whenever he walks, and he frequently participates in synchronized dances and routines with Shiki and Scarlet.

Beneath the comedy, he is an extremely loyal subordinate. Indigo remains committed to Shiki's plans for decades and devotes his scientific expertise to developing the biological weapons required for them.

Indigo is an accomplished chemist responsible for developing SIQ, a substance derived from the IQ plants of Merveille. SIQ dramatically accelerates evolutionary changes in animals, allowing Indigo and Shiki to produce unusually powerful creatures.

He can also fight directly. Indigo uses Chemical Juggling, producing explosive chemical spheres that he throws at opponents, and has demonstrated swordsmanship. His long history with the Golden Lion Pirates indicates that he was already a capable combatant during the crew's clashes with Roger's forces.

Indigo appears alongside Shiki during the events surrounding the Edd War and remains connected to him after Shiki's escape from Impel Down.

In Strong World, he oversees the scientific side of Shiki's twenty-year plan. His research into IQ and SIQ creates the mutated animals that Shiki intends to unleash as part of his campaign against the World Government.

Shiki is Indigo's captain and longtime partner. Indigo remains loyal to him for decades and provides the scientific expertise behind his plans.

Scarlet frequently accompanies Indigo and Shiki, including during their comedic dance routines. Franky becomes Indigo's principal Straw Hat opponent during the assault on Shiki's palace.