Seldom in my entire life have I encountered work with such power and emotional depth as Evangeline Walton's retellings of the ancient Welsh legends from the Mabinogion.
Suppose you are fighting a battle, and your enemy possesses an artifact called the Cauldron. At the end of the first day's battle, he gathers up all the dead bodies from the battlefield and puts them in the Cauldron. The next morning they are all reanimated and fighting on his side. Every day he adds all the fatalities to his army. Do you expect to win this war?
Finally, one of my favorite quotes is from this series, page 82 of Song of Rhiannon. Kigva asks his wife how she can possibly love him after her first marriage to Pwyll, which ended only with Pwyll's death:
For long I feared time, Lord, I who knew that it must take away my lover's strength and my beauty. But after Pwyll died I learned to bless it because now it had done its worst and could only bring me nearer to him. But when I had blessed it my vision changed, and I saw that it was a teacher as well as a destroyer. I saw that, great as was my love and Pwyll's, I must not make a prison of its memory, a walled place, shutting others out. For every walled place is truly a small place, cramping the body and the spirit. And every man and woman is worthy of love, and each calls forth a love that can be given only to himself or herself, never to another. And I remembered you, and knew that I loved you, and by that loving I need not cease to love Pwyll. It is hard to make it clear, that lesson.