@xXEchoWhisperxx guessed the herb correctly! I completely forgot the herb since I last edited this book 6 days ago, so if you wanna know what that herb was, go ask her or look in comments. Anyways, here's he riddle:

One of the cruelest,
Heartbeats of your life.
Is when one of your loved ones,
Is killed by a strife.
You use me to cover,
The stench of their death.
And I often have a scent,
That relieves stress.

I wish you good luck!

-Night