Small Council.
You may include non-loyal Small Council characters from any faction in your deck. You must include at least 7 different Small Council characters in your deck.
Reaction: After you win dominance, choose a standing Small Council character you control and have it gain 1 power. Then, if you control a King or Queen character, draw 1 card.
Link: Decklists
Rules FAQ
Different means different by title. Including two different versions of the same unique character does not count.
If a character cannot gain power for some reason (for instance, due to Karhold or Edric Storm (LotW)), you cannot trigger the reaction.
You can trigger the reaction when The Regent's Council is played.