I’ve read the book and host a game session, however there’s still something unclear to me, which is the Darkness…

I’ve read the book and host a game session, however there’s still something unclear to me, which is the Darkness part.

1. Does Darkness appear as a real entity like a shady figure or dark beasts? Or is it just an abstract power of corruption, existing inside every dragons? Or what else could it be?

2. The Seer’s move “Touch the Darkness” states that it triggers when the Seer consumes a piece of Darkness. What kind of actions should trigger this move? Is there an example?