I know you can get Mythical Artifacts from Dragon 6 where I normally Farm.  However, the drop rate is abyssmal.  I'm working on the get 5 Mythical Artifacts, and since my 2nd Mythical (a 5-star) I've pulled 80 non-Mythicals.  I was lead to believe that the combined (5-star + 6-star) Mythical drop rate was supposed to be 5%.   After 3,200 energy drained I'm becoming very disalusioned with Plairums RNG, not that I had a very high view prior.

Correction that's 1,600 energy on 80 Hard Dragon Stage 6 Runs.  

They drop from the 1st stage and increase in chance going upwards to 10.  You will need to be able to beat stage 10s of each dungeon for the missions. 

FK h10 is gonna give so many people fits 0_o

My next project! After shogun 25 :)

Before new missions I was sd24 sg0 fk0 😆 

Now 25/24/4  :) 

Sure will but at least there is a decent amount of options to at least beat it now.  Even if you can't farm it just beating it is doable. 

New missions actually making you gear champs, who would have seen it coming haha

I'm doing the Marius missoins. Obtain 1 Mythical Artifact from any dungeon. I did dragon hard stage 1 and 2 and got mythical artifacts but the misson did not complete. Anyone else struggling with this?