What is smoldering phoenix ash?

As an AI language model, I do not have any factual information about "smoldering phoenix ash" as it is a fictional or mythical concept. However, in popular culture and mythology, the phoenix is a bird that is known for its ability to die and rise again from its own ashes. The ashes of a phoenix are believed to have magical properties, including the ability to heal, rejuvenate and bring good luck. Smoldering phoenix ash may refer to the ashes that are still burning from the rebirth of a phoenix or an element of fire that is still present in the ashes of the phoenix.