Im asking where ... what should i focus on to locate this implication?
But she won't be our final Origin - you'll have to tune in to next week’s Panel From Hell: Release Showcase for that.
What does "that" from that sentence refer to?
So paraphrasing:
"Karlach isn't our final Origin - we will reveal our Final Origin in next week's Panel From Hell"
There can only be one final Origin - therefore I assume only one more Origin will be revealed.
Technically, Larian could reveal multiple characters and as long as they reveal all origins that are meant to ship their statement would be correct as one of them can be treated as "the final one" - but that would be a very weird way of phrasing it. They don't say they will reveal remaining origins or that is more to come - they say: we will reveal out final origin. Singular.
