Agreed with AIREAYE. With any stick you can flip it around and put a standard blade in the wrong end, but in general it messes with the kickpoint a bit, and gives you questionable performance. It's generally better to just slowly chop off the blade end bit-by-bit until you get to a thickness where you can fit a tapered blade in, removing the old tenon through heating or chiseling if necessary (some "OPS" sticks are simply a tapered shaft/blade setup that have been epoxied together, and you'll find the tenon in there when you saw off the blade). I've converted a number of broken sticks into tapered shafts this way, and it generally works out fine, just takes a bit of fiddling. If you have to cut it a bit shorter than you'd like, you can always add an end plug.
This won't work for any stick with a really long/extended taper (the Widow, but also a decent number of other high end sticks), and as AIREAYE mentioned it obviously won't work for Easton Stealth sticks with the crazy elliptical taper, but it should work for most sticks that have a rapid taper right near the blade, followed by a much more gradual taper higher up. I *think* the Ai.9 is such a stick, though I'm not totally sure.