Zoe Shadow

Does anybody have any good, original riddles?  Because Sensei Tezuka (Redthorn's Martial Arts geizer teacher... who is now one of Zoe's three Ninja Masters) likes riddles.  That much I know.  But I'm not the greatest at coming up with riddles for him to say.
Take into consideration that they're not supposed to be funny riddles... they're supposed to be cool and, erm, ninja.  I appreciate any help you can give.  :)
For starters, I need a descriptive riddle which can have multiple answers.  It should be able to apply to any element (fire, earth, air, water) as well as time.  So it's sort of a test to see which answer Zoe will come up with.  It vexes her... I like that word.  Vex.  It has an x in it.  Like... XEPHYR!
I haven't updated the "where I am now" section on the other excerpts page in a while just because I like the bit I put up last week.  It has Xephyr!  Sorry if anyone was waiting for a new one.

The green notebook is done.  Which means I've gone through the entire trio of matching notebooks: orange, blue, and green. 
Where to turn now?  Well, the best choice I had (I have a bunch of notebooks lying around, a lot of them too weird to put a novel in) was my old Social Studies composition notebook from this past 8th grade.  I only ever wrote like 8 pages in it, so it's all cool. 
It's in the following same collection, but more... compositiony.  It has polka dots.
Oh!  And check out the "other excerpts" page to the left.  I added a new bit there, where I type up the last few paragraphs of my most recent writing.  Should be interesting.  So read it.  :)  Thanks.  And comment here!  Questions (you know, confusion) are welcome.