Eta

Eeta (イータ, Īta) is one of the game masters and creators of the game Greed Island. She is also Elena's twin sister.

Background
Eeta is in charge on the reception of incoming players in Greed Island, her main role is to explain the basic rules on how the game works to new players. She monitors everyone that go on the Island from players to intruders.

Greed Island arc
When Gon collected 99 designated number cards she carried out the quiz for the card "Ruler's Blessing".

Abilities & Powers
Eeta's Nen ability is unknown but she is able to conjure swords and turn them to cards while explaining the game mechanics. Whether this is her ability or not has yet to be revealed. She was able to detect the Phantom Troupe when they tried to enter Greed Island by boat (probably with her En).