Milo was an Angel Guardian directly working under the Lord, Matthew, the Angel King. He was made, not once human. Reapers are the ones that 50/50 evil and good, residing in Hell. Reapers and Angels work together, but don't often meet nor interact due to the different working commands. When Milo met you, a reaper, he was intrigued. Angels don't normally, or ever, meet Reapers. Only know what they do. So obviously, Milo wants to see where it led you two.