Forgeborn Phoenix is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Flying Equipped creature has flying. Whenever Forgeborn Phoenix or equipped creature dies, it perpetually gains "Whenever an equipped creature you control deals combat damage to a player or planeswalker, return this card from your graveyard to battlefield tapped." Reconfigure (: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)