That's very beautiful.
Gwydion was a powerful wizard. To cut a long story short he made Lleu a bride out of flowers. Lugh was then the most monumentally stupid moron in the history of the world. He told his wife (who by this time was having an affair with another man) the only way he could be killed... which was pretty unlikely... I mean really. And THEN he set it all up just so she could see exactly how NOT to kill him DUUUHHHH.
It went something like... standing between the sand and the water, with one foot in a bath and the other on the back of a goat... yeah... THAT unlikely and just to make sure it never happened accidentally he set it all up to show her what not to do... just to avoid accidents you understand.
Then... to Lleu's surprise his wife's lover went right ahead and killed him, throwing a spear at him so hard it went straight through a stone.
When he was dying, and what a surprise that was, his uncle.. Gwydion turned him into a hawk and he flew up into a tree. He then turned the wife... Blodeuedd into an owl, cursed to fly only at night because if she was seen out in the day all the other birds would attack and kill her.
And then he had to charm Lleu down from the tree. If it was me I would have slapped him silly when he got there.