In my opinion, the most realistically obtainable team for Scarab King, and auto friendly too, is the team below. And of course, you can change one of the champions here as long as it does similar role, it should still work. 

Metalshaper is good but I prefer Miscreated Monster more since he can be viable in other content too. 

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Thank  you!  Do  any  of  these  champs  require  specific artifacts?  Like,  does  Armiger  need  to  be  in  Destroy?  

One of themshould have a shield-set to start the battle with an active shield. 

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this  is  my  line  up  for  easy.  Our  shield  champion  doesnt  have  to  be  at  60,  our  damage  dealer  does.

i  dont  need  the  vergumkaar  though  for  this  line up.  and  one  of  my  coldheart  is  in  destroy  set.

average  speed  is  above  180  though.  But  as  we  progress  to  higher  level,  we  need  to  have  increase and  decrease  speed  with  some  turn  meter  control  for  the  tougher  scarab  king.

i  hope  this  helps

No. In this team, no one should be in relentless. My team have 220+ speed, 300+ acc. 

Destroy is optional but it can make your run faster. 

Shield set is needed at least one of champion if you want to full auto the whole run. If no shield set, you have to save your champion's skills in the second wave before you go to the boss. 

Note that there is around 20-30% fail rate since Alure can do weak hits and may not be able to decrease boss turn meter enough to prevent it from getting a turn. 

I just watched a video  from Hell Hades, beating the Scarab King in normal with Metalshaper, High Khatun, Armiger and 2 Lvl 40 Elf Guards.

Just want to share. Possible in normal mode DT. Use that ring that gives u shield on attack and tier   that reducing enemys max hp

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