From the discord:
Paradox FateToday at 7:45 AM
@GM Sijin @QuixoticNeutral The SSA2 Prologue can be accessed, indeed, through the Pillar of Ice and Flame in Ouroboros.
GM SijinToday at 7:47 AM
Great! That's good to know, thanks. We'd probably still like to have the arc available without having to go through Ouro I think, but we'll see what the team thinks.