Or not.... eh... whatever....

Nova_Williams
Meimei152

So I've finally given a reason as to why Ian acts the way he does:

When he was a wee tyke his father wasn't around very often so he never had any or much fatherly support. And later when his younger brothers were born his mother had to spend a lot more time keeping them under control and took care of and all that. Ian had to help seeing as he was the only one old enough at the time and Mavelle couldn't take wee lil Heddwyn and Ollie out on a hunt. So he became resentful that his siblings received what to him was all of their mother's love and attention while he had to go out and do chores and such.
(Now Mavelle loved and still loves all her children deeply so it wasn't that she just didn't care, it was that she had a lot to handle as a single mom).
Ian, thinking it was all their fault that he was forgotten, began to hate his siblings and pushed them away both physically and emotionally.
Mavelle also died while they were all fairly young and it was left up to Ian to take care of them. But eventually he got tired of dealing with those he considered to have been part of the reason their mother was no longer there. (Thinking that if she had had less children to deal with she would've lived longer). So he abandoned them and left Sean to have to take care of their other younger brothers.

Then when he was much older and had children he at first at least tried to be the father his own hadn't been. But conflicts with other countries and other things clouded his time and he later realized that while he knew he was a father he had no idea how to be a dad.  So, not wanting to screw up like his own parents had, he thought that by pushing his children away as he'd down with his siblings would lead them to simply forget about him and learn to be their own people and do better in the world.
Though he realized much too late that this was a wrong decision but has no way to make up for it nor to turn back time so he continues to act as he does and pretend that nothing is wrong.
He wants to have a good relationship with his children but knows he's already messed up and now thinks it'd be better if they all just moved on without him.

Quite the similar situation happened with Iona. Though whereas Ian never planned on having chilled Iona had dreamed of it at least once. But certain things prevented her from being the mother she had always hoped to be and she ended up falling down the same path as Ian.