Anselm Nightshade used to be a Shadowhunter
- We know that Shadowhunters can be turned into vampires and Nightshade is a Shadowhunter name (Clary's maternal grandmother was a Nightshade).
Ty is not the child of Andrew Blackthorn.
- Ty has gray eyes, while his father Andrew and all of his siblings (even his half-siblings who have faerie blood) have blue green eyes. He also has black hair, while his father and all of his full siblings have brown hair and his half-siblings have blond hair.
Ash does not posses enough demon blood to turn him evil
- Sebastian (Ash' father) was infected with demon blood before he was born which caused him to become evil. It is thus pretty reasonable to assume that his son is evil too. However there is one thing that disproves this: his eyes. When Sebastian was born he had black eyes and he was evil, but after the heavenly fire burnt away his demon blood, his eyes became green and he turned good. Ash has green eyes, so that means he is good too and that he does not have enough demon blood to turn him evil.
Ty is gay
- Word of God says that one of the Blackthorns is gay and two are bisexual (confirmed to be Helen and Mark). There are four male Blackthorns: Mark, Julian, Ty and Tavvy. Mark is already confirmed bisexual and Julian is confirmed straight, so that leaves Ty and Tavvy. Tavvy is only seven years old and even if there is a Time Skip of a few years between this series and the sequel, he would still be a child, so it seems unlikely that the series would explore his sexuality. This leaves Ty as the only possible option for the gay character.