The Knight adventurers are a trio of knights, adversaries of the Mantenientes, each with a banner bearing a personal sigil.
In medieval tournament terminology, the Adventurers are the challengers who defy the defending group: each carries his own sigil on his standard, marking individual identity against the collective emblem of the Mantenientes.
The probable context is the Eiffel Tower Tournament (1890 A.D.A.) or an earlier tournament in the cycle of the Regulators in Antiterra.