A boy with no magic knows a girl that has time magic in her blood and her father has 900 titles. (I'm not sure about the number of titles and the meaning of them but I just remember he has a lot of them.)
The boy is also a bit of a psychopath.
If the girl gets hurt enough she turns into an adult woman. Her normal age is about 10 to 12 and she has red hair if I'm not mistaken.
Also wizards can't cross the ocean or something like that?
This is Shin Honkaku Mahou Shoujo Risuka.
The elementary schooler unlike any other, Kugi Kizutaka, is searching for "useful pawns" in order to achieve his own ambitions, comes to learn of Mizukura Risuka, a magician with the title "The Red Witch of Time." Risuka had left the Kingdom of Magic through the Gate, chasing after her father, a great mage called both "a God" and "a Demon." An unpredictable and unchained magical tale!
Synopsis covers her father having multiple titles; there's probably more, but I don't recall for certain. She does have red hair and is young most of the time.
That's the two protagonists, with Risuka in her normal, young form. She turns into an older, ~20 year old witch if she dies or loses too much blood.
