Whats the quickest ways to farm medals?

I've been doing a lot of Vladimir's Castle on normal and hard but I feel like its wasting a lot of time. So what would be the most efficient and quickest way to farm for medals. ty and peace :3

 

hacking

 

Al hata hard or Dh 13 hard in my opinion. Fast boss modes and a lot of medals.

 

Daily Reward Box. I've got like 23k medals.

 

^ Agreed, I stack daily rewards and open all of them at the end of the week, easiest carats and medals , two birds one stone.

 

That's actually clever because the more boxes you open at the same time, the better chances.