501.1a As a ready step starts, the turn player readies all physically exhausted cards in play he or she controls. Any modifiers created “as [that turn] starts” are also created simultaneously. None of this uses the chain. Next, a priority window opens. As that window closes, the ready step ends.
You can play an instant card or use the power of a card in play you control, and add its effect to the chain. It will resolve before the effect of Wavestorm Totem but it won't stop its effect because it was already in the chain.
So, you can respond to the triggering of Wavestorm Totem but not before it triggers.
The only thing I win is honor...