The Nephele Timeline Branch Event is a point where reality branches when Grxxlt interferes and sends “The Party” back in time about 3 days & new things occur that change things for the branched timeline as well as create paradox issues. This event takes its name from one of the biggest shockers of the branched timeline, which is the return of the Nephele Sisters who were deceased in the original timeline.

1. In the original timeline Eyrun dies at the Rusty Cave while her and companions attempt to save Skip who is trapped there. In the changed timeline this never takes place, meaning Eyrun does not die there. This version of Eyrun has the Whispering Teapot and it spilled the tea about the new to her Vesper being part of her own sister's murder which triggered Eyrun, because of course it would trigger Eyrun.
2. Since The Party was never at the Rusty Cave, Skip was never saved by them¹⁾.
3. The knight named NueNue who was summoned to be a loyal companion for Urist by the infamous Deck Of Many Things was never summoned at the Rusty Cave, and since NueNue wasn't part of the confrontation with Grxxlt she was not sent to the alternate timeline, thus Urist has no knight. However, she probably exists in Orangevale but has no knowledge of who Urist or any of these people involved are.
4. Phoebe Nephele in the new timeline not only didn't get into the situation of going to the Rusty Cave to retrieve Eyrun's body, but she also figured out for herself that Urist, Jules, Alimir, Matilda & Vesper were threats and escaped them by running away from The Card House when they were all gathered there.
5. Urist, Jules, Alimir, Matilda & Vesper kill their other selves so that there is only one of eat of them in this new timeline. This makes them the official adventuring party. We learn that if there are two of someone in a timeline in this campaign setting that their life force is halved between the two of them, which creates conflict as a general rule.
6. Jules & Urist, never having almost died at the Rusty Cave, escape The Lugo Contracts because no such contract was ever created in this timeline²⁾
7. Alimir who had used the Warlock Well to solidify his god as being Bobo Maf in the original timeline found that unchanged. This time around though by tossing a duplicate Fire Opal Staff into the Warlock Well also managed to restore his lost memories by striking a deal with a powerful fire elemental in another realm of existence. This vastly enhances Alimir's knowledge about himself and his circumstances.
8. Matilda who had tossed the Shovel Of Alden & Kelthor's Book Of Great Awareness into the Warlock Well in the original timeline found that the effects of that remained in place. However in the new timeline both the Shovel Of Alden & Kelthor's Book Of Great Awareness also remain as valid items never having been tossed into the well.
9. When The Party returned to The Card House prior to the point where they had encountered a drunk Grxxlt outside in the original timeline, they instead found him working on drinking inside, safely. Grxxlt seemingly with no knowledge of the encounter he'd had with them, didn't cause any issues.
10. This all concludes with Eyrun no longer being an official part of the party, but they have her drugged with Mistwood Sap in a room at The Card House. Meanwhile with Phoebe Nephele running away from the party likely with a new agenda of her own, the future is uncertain. So in this timeline, Nephele's are not wiped out of existence and that is a fairly huge deal in and of itself.