Memento Mori Series by C.N. Crawford

Seventeen-year-old sorcerer Tobias Corvin tumbles through a blizzard and arrives—half frozen and half dead—in another world. Trapped in Boston, he tries to blend in at an old boarding school while secretly plotting to save his home. But if anything can distract him from his mission, it's the wild-haired and intriguing Fiona. She is determined to learn the truth about his dangerous magic. When a spectral army from Toby's world begins slaughtering Bostonians, he and Fiona must stop the carnage... moreSeventeen-year-old sorcerer Tobias Corvin tumbles through a blizzard and arrives—half frozen and half dead—in another world. Trapped in Boston, he tries to blend in at an old boarding school while secretly plotting to save his home. But if anything can distract him from his mission, it's the wild-haired and intriguing Fiona. She is determined to learn the truth about his dangerous magic. When a spectral army from Toby's world begins slaughtering Bostonians, he and Fiona must stop the carnage. They face unspeakable dangers unearthing the dark secrets of New England's past—a past that holds the key to saving both worlds from destruction. less

Most girls her age worry about boys or what to wear, but Isolde has bigger problems. Ever since Isolde's brother died, her mother spends her days ranting about magic. Now Isolde's been forced to leave her beloved swim team, to hide the burns her deranged mother inflicted. When her mother humiliates her in front of the whole school, Isolde takes refuge in the sea. Its green depths have called to her all her life. But when a storm rolls in, it brings lost memories crashing in... moreMost girls her age worry about boys or what to wear, but Isolde has bigger problems. Ever since Isolde's brother died, her mother spends her days ranting about magic. Now Isolde's been forced to leave her beloved swim team, to hide the burns her deranged mother inflicted. When her mother humiliates her in front of the whole school, Isolde takes refuge in the sea. Its green depths have called to her all her life. But when a storm rolls in, it brings lost memories crashing in. Maybe Mom's paranoid ramblings weren't so crazy after all. Trapped on a ship with Lir, a disturbingly handsome witch, she must confront the nightmare of her own past--and decide who she really trusts, before she's lost at sea forever. less