What is your best mele dueling character?

[Cauhtemoc]

The hammer travels outwards in a spiral, starting at -60 degrees from the top of the caster. It then takes 240 degrees for the hammer to be far enough from the caster to allow a gap where another character can stand without getting hit. So there are a total of 120 degrees, or a third of a revolution, where you can stand without getting hit.

So to answer your question...

Yes, if you teleport right below him, the best choice would be to Whirlwind to his front.