Masquerade is the last jinn of Felos and the one person that Avie believes can bring peace to the land. Avie's naivety gives Alaston the catalyst he needs to trap Masquerade. If Alaston can get Masquerade's gem close enough to the jinn, then the jinn's power would be his to wield. Alaston arrogantly believes just because Avie's is his betroth that he can talk her into anything. It is, after all, her duty as his soon-to-be-wife to obey his commands anyways, or so this is what he believes.