Here lists the vendors that offer rewards for "Sequin of Solomon Island". The NPC you are looking for is "Council of Venice Envoy". They are generally located near a mission hub and sell various pieces of gear: Weapons, Major and Minor Talismans. They also sell Casting Toolkits which will change the appearance of an item.
Nearby you can generally find other vendors such as the Chemist and Apothecary which sell consumables and toolkits for PAX instead of Sequins of Solomon Island.
Nearby you can generally find other vendors such as the Chemist and Apothecary which sell consumables and toolkits for PAX instead of Sequins of Solomon Island.
