Power of Transcendence.
Generally speaking, this was a fan-created ability from some derivative works Luo Mu had read before traveling through time.
It had never been officially defined as a special ability.
Tracing back its origin, it should have been an ability possessed by Sheena, a supporting female character who served as the guardian of the Mishina Ruins in the Movie Theater Version.
Sheena could form an invisible bridge with Pokémon, communicate with them telepathically, and use her own heart to soothe their emotional turmoil. However, if their rage was too powerful, the telepathic connection would be severed unilaterally.
Besides her, Damos, Sheena's ancestor and another key figure in a Movie Version plot, possessed this ability as well.
Frankly speaking, this ability was more like a watered-down version of Aura.
Once the other party's emotional fluctuations became too intense, telepathic communication became completely useless. It was somewhat underwhelming.
If Ash had not been there to save the day in the Movie Version, Giratina, who had chased Dialga out of the Reversal World to beat it up, would never have given Sheena any face.
So aside from telepathic communication, the only praiseworthy thing about this ability was that it seemed capable of calling out the Time-Space Duo.
The reason fan works named it the "Power of Transcendence" was probably because Sheena and Damos would recite the line, "Transcendence, the laws of time and space," whenever they used it.
But clearly, a gift bestowed by Arceus, the "original," would naturally not be an ability with such enormous flaws.
The abilities seen in the movie—telepathic communication, sensing emotions, confirming the locations of Pokémon connected to oneself, and so on—were naturally standard features.
But beyond that, there were clearly other differences.
Even Luo Mu, the ability's owner, could not quite make heads or tails