Answer:
What can't you see, hear or feel, until its too late. What shadows love, and shopkeepers hate?
I build up castles. I tear down mountains. I make some men blind. I help others to see.
A seed am I, three letters make my name. Take away two and I still sound the same.
Creatures of power, creatures of grade, creatures of beauty, creatures of strength. As for their lives, they set everything's pace. For all things must come to live. Under their emerald embraceย Either in their life or in their death.
High born, my touch is gentle. Purest white is my lace. Silence is my kingdom. Green is the color of my death.
What is so fragile that saying its name breaks it?