We know practically nothing about his personality and very little about his life in between the last chapter and epilogue's times.

So the reasons must lie somewhere else. :D

He immediately became one of my favourite characters when he was first introduced...(in no ranking order) because...

X He was a baby in the middle of a war. Something sweet and happy.
X He's son of a werewolf but not one himself.
X He's son of a Marauder.
X He's son of one of my favourite characters.
X He's a metamorphimagus.
X He was orphaned which brought some darkness into the character, balancing the picture a little.

The only thing I don't like is what the Epilogue receals. For many matters and not just Ted, so I mostly just ignore it in my fanfiction.