How to fix the Lens on Hurricane Hao?

Cover it with some grip tape.

Do you actually feel the lens sitting loose? Can you wiggle it about, has it sunk in where it shouldn't be?

If that's the case, you might be able to get it in place again using a little suction cup (ie a toy arrow). You'll still have to fix it in place, though. A bit of glue might do that, but you'll need to get the glue inserted where it matters, which may be hard. And it may not work on these surfaces if you don't get them clean enough for the glue to form a proper bond.

A more radical approach would be in deconstructing the handle. I've done this on occasion by removing the rubbers, applying head to the handle and gently prying the handle loose using a flexible cutting knife. If the lens is fitted from within, you'll probably need to remove that handle half only and can work from there.

Be careful when taking apart, and equally careful when putting together. If this sounds too much like art class for you, well, sorry about that.

That clicky sound may also be a partial wood fracture. Does the blade still feel the same?