The Thestral and The Phoenix

Why was Gellert Grindelwald sent to live with his aunt Bathilda Bagshot, what did she think of him? She introduced him to Albus Dumbledore, but how could Albus ever love someone like Gellert - What drew Albus to him? And what if Albus was not completely blinded, but confronted Gellert about his darker plans from the get-go? /1st chapter is M, but from 2nd chapter on it's less heavy