Answer:
My children are near and far. No matter that I know where they are. The gift I give them make their day. But if I were gone they would wander away.
My life is often a volume of grief, your help is needed to turn a new leaf. Stiff is my spine and my body is pale. But I'm always ready to tell a tale.
I am never quite what I appear to be. Straight-forward I seem, but it's only skin deep. For mystery most often lies beneath my simple speech. Sharpen your wits, open your eyes, look beyond my exteriors, read me backwards, forwards, upside down. Think and answer the question...
Just head and foot yet never tires of dancing.
Useful tool for who in darkness dwell. Within you, corrupting like a deadly spell.
I am your mother's brother's only brother in law. Who am I?