A sigma themed skin to go with the Erelim syandana and pairing this in it (or making it not screw with the theme of both cosmetic items), would be awesome IMO. The helmet doesn't need much if any changes to it, because, as it is now it thematically goes with vanilla, deluxe and prime Titania which is quite the artistic feat IMO.

If and when you do decide to make a skin's to go with this helmet and the mentioned syandana, it would be amazing if you could make the texture's theme of the body skin sort of mesh the themes of both the helmet and Erelim syandana in whichever way you wish. It would also be amazing if you kept in mind how it would look with Titania prime's detail if possible, but best of luck to you should you begin this endeavor