Ivar

Ivar is a member of Sluagh, brother of Fyfe, uncle of King Sholto. Acts as Sholto's bodyguard in Mistral's Kiss.

Mistral's Kiss
Sholto has Ivar, Fyfe, Black Agnes and Segna the Gold with him when he catches Meredith and her guards in the dead gardens inside of Sluagh sithen. Ivar proves to be apt observer - it is him who points out Meredith and her people couldn't get muddy in their gardens, and that it is obvious none of them knew about  Sholto's mutilation.

He is also the one sent with Black Agnes to help Segna, when she gets impaled on spiked bones rising them the lake in the dead gardens of Sluagh.

After Sholto and Meredith appear back in the dead gardens on Island of Bones wielding the wild magic, Ivar and Fyfe ask their king to remake the Sluagh into what it once was, and not to change it to be more like sidhe. Sholto calls the wild hunt, but it fails to recognize him as a king of Sluagh and attacks him. Both his uncles defend Sholto, and sacrificing their lifes they buy him enough time to escape.

Swallowing Darkness
Meredith wonders if he is father of Iomhair and Chattan, but decides not to ask, since she was around when Ivar died and she doesn't want to be blamed for his death, even if it was not her fault.