However, there was one very important caveat to the use of this technique. It could only be used by those with the Rebirth Flame. If one attempted to use it without those unique flames, all that awaited you was death!
It was likely because they knew this that the Fire Phoenix Clan didn't keep a tight lid on this technique. Dyon laughed as he read about how Orcus got swindled into trading his comprehension of the Death Dao for this technique, only to realize he couldn't use it even if he wanted to.
At the time, Orcus was worried the Elves would interfere with his Higher Existence tribulation, so he wanted to skip the tribulation entirely if he could. He had always heard that the Fire Phoenix Clan had an exaggeratedly high success rate, so he went to them with some offerings. Since they were both Flame Bird Clans, they had a fairly good relationship to begin with.
Still, none of this mattered now. Madeleine ended up benefitting greatly!