"The Legend". Problems with the walkthrough.

I thought I could quickly reach Karador, but the danger seems too great for various groups of troops. Also, it's a pity that I can't learn "Inquisition" yet. Is there any way to quickly get a few Spirit runes? And could you tell me a little about Karador's strength so I can prepare for the battle with him?

I accidentally wandered near Karador's castle at level 18 and approached it, but he chased me away. I thought about trying to fight, but it didn't work (apparently, I need to complete a quest first?). And around the castle, there are formidable squads with dozens of black dragons in their ranks - I had to retreat; it's still too early for me.