Mary Silverlock (IPA(key) /mɛr'i sɪl'vr'lɔk/) was the Grand Templar preceding Trace Legacy. She is also Raine's mother through a relationship with Euchre in human form. She foresaw that Trace had phenomenal potential that would be triggered when he found a cause.
Mary has a fearsome temper, exhibited when Trace and Lady Nora destroyed her front yard in a mock fight in an attempt to impress Saria. Her rage, and her use of magic during it, caused Nora, an old and powerful dragon, to flee.
Mary found out that Euchre was a Keidran through an interrogation of Roselyn, who had been captured in Human territory and was about to be hanged as a spy. Roselyn had called for Euchre while on the gallows and it became clear to Mary, upon seeing the reactions of Roselyn and Euchre to seeing each other, that they knew each other. Mary and Euchre broke up over this before Raine was born.
Trace overthrew Mary, turned her into a Keidran and called guards to capture her. Euchre had joined Trace's coup against Mary on the condition that Mary was not to be killed. Trace had arranged for Mary and Raine to be sold into slavery, but Euchre rescued them. Mary regained her humanity through a deal with Ephemural, seemingly appearing under her/it's influence throughout the early chapters, leading up to Chapter 6, giving Ephemural access to Flora.
Mary was last seen talking to Trace in his cabin shortly after the battle with Ephemural thanking him for saving her though she still hadn't forgiven him for what he did to her. It is not known if Mary and Euchre have reconciled, but they were working together with Trace against Ephemural during the battle.
She is mentioned periodically by Raine, especially when she explained her backstory.