Acer Malum Magnus was the notable trow that Ewan spoke to. Ewan was sent by the scholar Antero to find out more about the Trow and Acer Malum Magnus is the one who spoke and regaled Ewan with his people's history. Acer may have been a Trow Priest, it is conceivable that a trow with such innate knowledge to be of scholarly stock--Acer was probably like the Trow Priests of Myth 3, and therefore the last of their kind--and he is arguably the best Trow given that he is the only notable one.