Skarsgard wrote:This relic gives a 5++ bubble if the character hasn’t moved in the previous movement phase. How does this work for turn one? Does it start “on”?
Oh boy you've opened a can of worms with this one.
The simple
tl;dr answer is we don't know, both arguments have merits.
Basically, the answer has two camps. The first state that because you haven't declared a move this game, you must have not moved, thus you benefit.
The second states that because there has not been a previous movement phase yet, it can't be active because you've not had a movement phase to not move in.
Until
GW fixes it with errata or Special Snowflake
FAQ, you have to debate pre-game with your opponent.
FWIW I would say that until
GW says otherwise, they can't have the status of "does not move in your Movement phase" because they haven't had a movement phase to not move in, thus it doesn't work in the first turn if you're going 2nd.