In the time before the Tuatha Dé Danánn came into Ireland there were other tribes in the land and indeed older Gods. Lír is the name of one such ancient deity and he was a being of some importance to the island nation as he was the God of the sea itself. Yet for all of his power and influence, we seem to have no tales about him, but we do have many tales concerning his son, the Mac Lír, known as Manannán.
There is a saying that knowledge is power. The knowing of a thing leads to understanding and in understanding we are empowered. Might I suggest you take some time to get to know Mananán Mac Lír, so that you too may be prepared for when the Otherworld calls.