Sure enough, Yzzil fell ill and died in two days, just as Nyleve cursed. This was but the first of many powers the two would aquire.

....

"Yzzils death was a tragic loss. Our medicines could not cure her, nor did our healers know what illness she aquired. We will mourn her for many moons," Shadows voice rang accrost the clearing filled to the brim with cats of all colors. Evelyn and Nyleve were at the back of the crowd, Evelyn looking somber, and Nyleve looking emotionless.
"How do you think she fell ill?" Evelyn murmured to her sister.
Nyleve meerly grunted and replied, "I don't know and I don't care, so long as we don't catch it." She stalked off to her den. Evelyn sighed, watching her go. She sensed something was off about Nyleves responce, she had dismissed it too soon, and looked not a tad bit sad about her own mentors death. Nyleve sure is a mysterious cat.
There were many rumors floating about the camp. Some said she was poisoned, others said she was cursed, yet no one could think of how or why.
Lizzy became Nyleves mentor. Such is the way when one mentor dies, their sibling becomes the mentor to the dead siblings apprentice. An easy, simple solution.

....

Evelyn and Nyleve sat quietly. In front of them sat Lizzy, teaching them various Exnix customs and history.
"We live in a complex, efficent land. Our country is dotted with many groups, like ours, called clowders. Each clowder has one leader and a deputy, both siblings, until one dies. Then, the remaining sibling becomes leader, appointing some other cat as deputy. When that leader dies, the new deputy becomes leader, then their sibling becomes deputy. Right now, our leader is Shadow, and our deputy is Wodahs, Shadows brother. Our healers are Lou and Uol. There are many cats in our clowder, so it's hard to remember them all.
"One thing I am sure you've heard about is the necklase you get when you become a loyalfur. This necklase symbolizes that you've grown and are now a higher part in our society. On the end of each necklase is a symbol. Each cat has a unique symbol, though I'm sure it's repeated every few years. Look at mine for an example. It's the same orange as Yzzils fur, and the symbol is a feather. I remember being so excited to find out what symbol I got! Some say they show what your heart is. Not litterally, but, like... your inner personality. Your true personality.
"To get your necklase, you need to be appointed a loyalfur by your leader. After that, you must travel to the top of fang mountain, where the the rocks are as sharp as fangs, the plants are covered with claws, and the water tastes like blood. It's a long, horrible journy, filled with danger, but if you reach the top there is moss as soft as kitten fur, and the water is as clear as crysyals. This is where our ancestors in the stars come down from their heaven and put the necklase around your neck. There is a secret way back that they show you that is safe and not horrible. You have many more moons of training, but I believe you will make it."
Lizzys speach left the two in stunned silence. They padded away after being dismissed, heads filled with thoughts about what their symbols would be.