"...each player chooses an Akua they did not choose in step 2 and erases the Mark in that Akua's selection space..."
In a 2 or 3 player game, there will be an Akua no player has chosen. Can you choose this Akua in step 3? Or is it implied you MUST choose an Akua that has been selected by another player.
For example, in a two player game...
In step 2, I choose Red and you choose Blue. Can I, in step 3, choose Green? Or must I choose Blue?