Reunion: The Sound of the Providence: Season 2 (2020)

Lost Tomb: Reboot is the events occurred 10 years after the Tomb of the Sea and kinda 18 years after Ultimate Note. it is related to this series of Dao Mu Bi Ji

Both of the same series of lost tomb dramas and movies ,, with the same characters but different actors

It's part of the same series, it's a sequel, it has the same genres and some actors play here again..............

Reunion: The Sound of the Providence is the first season of Reunion: The Sound of the Providence following were season 1 left of at and continuing with the same actors.

The Lost Tomb is the prequel of Reunion: The Sound of the Providence Season 2. It contains the same characters, but with different actors.

The Lost Tomb 2 is the Prequel of Reunion: The Sound of the Providence Season 2. It is also the sequel of The Lost Tomb which is the parent story The sound of the Providence.
The characters are the same, but not the actors.

The Mystic Nine is the prequel of the The Lost Tomb series. The time period is 50 years before the main event, so all the characters are different.

It's the side story from The Lost Tomb like Reunion. The timeline is 2 years before reunion. It's more focus on the nine families and ofc, we still can see Wu Xie.