Which star is used to represent the Arcanum 6 and why?

Answers from the books of Samael Aun Weor

The struggle between the two ternaries is in Arcanum number 6. This is the affirmation of the Internal Christ and the supreme negation of Satan. Arcanum number 6 is the struggle between the Spirit and the bestial. Number 6 represents the struggle between God and the Devil. This Arcanum is expressed in the Seal of Solomon. The upper triangle represents Kether, Chochmah and Binah; the resplendent Dragon of Wisdom (Father, Son and Holy Spirit). The lower triangle represents the three traitors, who form the antithesis of the divine triad. They are the demons of desire, of the mind, and of ill-will. From moment to moment they betray the Internal Christ, and are the bases of the ego (Judas, Caiaphas and Pilate). This lower triangle is the Black Dragon.

Samael Aun Weor. Tarot and Cabala