That Tattooed man should have appeared near the Hall of Wonders (and not here!), when you have met Jusam and six bandits have attacked you.
What happened that time? You talked to Jusam, bandits appeared and did a Tattooed Man say "Kill them all?" and then attack you?
When he suffers enough damage, he should say something like "I have no time to play with a bunch of idiots" and then teleport himself away, but as I said this should happen near the Hall of Wonders and not in FAI
I think this is what you have done: you killed all of the six bandits near the Hall of Wonders, talked to Jusam and went to the house, but
left the Tattooed Man there (and did not cause him enough damage.)
Am I right?
If you don't want to re-start the mod from the Hall of Wonders battle, I think I can help you:
1. First method: If I am right and you left the Tattooed Man near the Hall of Wonders, he should still be there! Go back, and cause him enough damage, until he says he has no time and disappears. Then go back to the FAI. The disadvantage of this method is that the Tattooed Man who appeared in the FAI will still be called Tattooed Man when you return. (Normally in the mod, he should be called Grachus in the FAI, that's his real name).
2. Second method: Are you familiar with CLUAConsole? In FAI, after the Tattoeed Man says he has no time and teleports himself away, use
CLUAConsole:CreateCreature("bw05grac") at the same place when you are prepared to an enormous battle. A person called Grachus will appear (he is the Tattooed Man), and when you kill him, you can find the Crystal among his items. It is a very tough battle.
Please let me know if this has solved the problem or no.