Originally Posted by
Malchar
Are we still assuming that we have a furnace of rath? Also, I'm not sure what the Nomad is contributing to the combo here. Furnace and Nomad are both replacement effects, and the controller of the object receiving the damage gets to choose the order in which the replacement effects are applied. However, each replacement effect can only be applied to a single damage event once. Redirecting damage with the Nomad does not make it a new damage event.
To answer your question, suppose we have Nomad and Reckoner on the battlefield, and someone shocks the Nomad. We activate the Nomad ability twice in response to shock, and we target Reckoner with it. Now, when shock resolves, it will deal 2 damage to reckoner instead of to Nomad. It still counts as a single event since the shock is still the source dealing the damage when it resolves.
Now, if we add furnace of rath, we can do some interesting things. If someone shocks Nomads and we redirect the next 1 damage to Reckoner, then we apply furnace after that redirection, Nomads takes 2 (after doubling) and Reckoner takes 2 (after doubling). Now we can have Reckoner shoot Nomad, and redirect one of that back to the Reckoner, then we can apply furnace after the redirection again, so both Nomad and Reckoner take 2. This can keep going, but I don't think it's very useful except to illustrate how the mechanics work.