FAQ (for anyone who gets stuck "deeply" somewhere) @.~

[zykox]

After losing the horn just ask "Borsha" companion about the where about of "Dark armies" like Dark knight & Dark hunters ... that is a hint given to me by "Secret man" in camp when I asked him about rest of gems way to find.
Plus going around killing Dark armies specially Dark Knights gives you more experience & more valuable loot.

You can ask "Borcha" about all dark armies (Dark Pilgrims, Dark Hunters, Dark Knights, Dark Avengers, Dark Inquisitors) as soon as Ymira has joined your party, when he gets the "Eagle Eyes" ability.

You can ask him about the Lost Knight as well, if you have met him once.

Dark Armies in general have a lot of loot, and give a chance to drop legendary weapons, but you'll never get any prisoners.

 

[vaskim34]

I've gathered all requisits to gain acess to the horse market and still nothing 

 

[Master_Ike]

Well I've got a question for you: I am running circles around the lake, and have no idea how to get into the dungeon. What must I do??? HEEEELP!!! 

 

[OldGreyBeard]

Well I've got a question for you: I am running circles around the lake, and have no idea how to get into the dungeon. What must I do??? HEEEELP!!! 

If you received the map from the Lost Knight, it will show up as you march around/near the lake. If you don't have the map, it will NOT show up.

If you haven't found the Lost Knight, there are posts on where to look for him elsewhere. I'll leave it to you to find him.
I usually dedicate a few days to just following him and talking to him once a day till he gives me the map. Then I hit the dungeon when I feel up to it.