Ask who he is.

Summary It's unbelievable... Didn't your Star of the Land tell you?
I am... the "guide" to help you restore your memories.
Eibhlin... am I merely an illusion...?
To overcome the Black Death NPC Knowledge Item and come all this way... an incredible feat.
I can hardly believe what I'm seeing!
How did you manage to cross the gate and survive the Black Death?

Summary Don't you recall the day you sought me out?
You came to me, a big guy engrossed in alchemy.
Back then, amidst the mockery,
you followed the rumors to me.
You were eager to learn from an outcast like me,
yearning to defy death with alchemy...
But how? The Black Death NPC Knowledge Item is an inevitable end.
It was something impossible to challenge.
Yet, you set off, determined to overcome it.
...Haha. Now it all adds up.
You made me your guide,
Just to mock me for predicting your end.
The secrets I knew were pale in comparison to yours.

Quest Text Eibhlin... How is this possible? You're...?
I can hardly believe what I'm seeing!