Where is he located? I beat hard labyrinth and never saw him. Is he on expert?

Where do you get the ore that allows you to add things to your weapons such as speed 3?

Where do I get an undead gem and how do I add speed 3 to my weapon 4 times for gold guild boss?

I can't find subquest 19 or 20

I am having a hard time opening the door to the first area. I found 3 treasure chests that made the door start disappear but I can"t find the last one. I looked all over and can't find the last chest to open the door.