I would consider making Idyn the middle name and use a king's or historic first name of the James, Matthew, George, Edward kind to balance the unusualness of Idyn. I am concerned that unless you live in a very arty community, the kid will get teasing in school over his name, especially since Idun is a girl's name. (I had to give up on Aurora as a possibility when my sister pointed out that mean kids would probably call her Areola, and a friend of mine had to give up on Phanie, since it would automatically be turned by teasing kids into Fanny.)
Elijah, skylar, skylark, noah