Power Level Edit
Undefined, but presumably low. Akua is shown to be unable to defeat the Catherine Foundling as the Squire in physical combat, although her focus was always more on magic and trickery. Heiress often employs mercenaries or manipulates powerful individuals to make up for this weakness.
Heiress is a transitional Name like Squire and Apprentice. However, unlike Squire, which is strongly linked to both White Knight or Black Knight, or Apprentice, which transitions to any available magical name, Heir(ess) can transition into any available role that is available. Akua became The Diabolist simply by becoming famous for using demons and devils.
Special Powers Edit
The name Heiress does not strengthen the user physically but it does allow the user to manipulate other through more subtle means. Heiress' power works indirectly allowing her to manipulate individuals on a chessboard. The name also seems to enhance her magical abilities allowing the user to spar with the Apprentice.