@WatchdogCZ if you don't mind me asking, why is your MM has that high of Att?

I  don't have MM, but AFAIK  MM have no skill that uses the Att stat.

@WatchdogCZ Can you run your MM geared as he is  once in 12-3 to see how much time it takes?

Less than ideal rolls on the artifacts, I am afraid.😀

Sure, as soon as I am done with tickling Spider 18 till she bursts and dies. Or kills my team. *sighs*

Edit: 12/3 was cleared by Miscreated Monster in 42 seconds.

To answer the last 3 people. Athel can solo Brutal I just found out, but right now she is rocky, MM does it too in more time but much smoother. I'm not caring to much about time saved, but more about who will be most consistant, I also have a shield set on MM for that very purpose, and getting him higher will be a huge help. i don't intend on getting rid of Athel right now, but I did forget there are better nukers out there, so I think that makes my decision for 6starring MM first. Better to have consistancy than speed in my opinion.

Thank you all for your input, much appreciated.

@shadowkin45 you're the one who knows what your team needs and how to best approach the game with the team you have.

But I do have to say farming 12-3 or 12-6 needs to be fast, it needs to be under 30sec, not because for showoff, but because how many things you have to do in this game, having farming XP fast means you have time to actually do other parts of the game (like Arena, Faction Wars, Clan Boss, etc etc)

The principle for farming 12-3 or 12-6 is for the hero to be fast and can kill everyone in one shot and to not take any damages (or at least the damage can be ignored without the need of the hero taking a turn to heal him/herself), that's why I recommend that heroes used for farming are specialized glass cannon,

i

That's my Athel, 27sec average on 12-3, 9sec record fastest, 100% success rate

I think I can squeeze 7-8 seconds from the average but for me anything under 30sec is enough and I don't think I want to use more speed stuffs for her.

So yeah, that's my reasoning on why you need to get under 30sec in a farming run and the principle to achieve 

@SunnyRay  I did Campaign runs with my Miscreated Monster

My M.M can Solo Brutal 12-3 in 25 seconds

My M.M can Solo Nightmare 12-3 in 5:08 seconds

M.M is 1 of the very few heroes which can Farm Nightmare Campaign.

However, I think most people don't like Farming Nightmare Mode.

relickeeper is the one that i would suggest.

IT is the god of farming.. if you are looking for it. The game doesn't get interesting until you 6 star at least 4 of the champions

apothecary is a must 6 star but do it after some time. though a rare one. you will feel its value.

coldheart is also good for dungeon. though, you should max this one later cause u will need good artifacts for it to be good.