The  reason  I  asked  you  about  counter  attack  is  because M  King  is  relatively slow.

Counter  Attack  Buff  allows  M  King  to  take  turns  while  being  slow.

It  is  a  very  good  Arena  combo.

I  like  Rhazin  +  Seeker  combo.

I  run  a  similar team.

Based  on  what  you  have  said,  I  would  build Rhazin  has  nuker  of  team.

I  would  build  M  King  as  Shield  Set  /  Immortal  Set   wearer.

I  would  probably use  Scyl  of  Drakes  instead of  M  Monster.

M  King  has  highest  HP  in  game.

I  would  play  off  that  fact  by  using  Shield  set  on  him.

I  am  thinking  of  the  following:

HP  %  Gloves 

HP  %  Chest

HP  %  Shoes

Wont that shield get stripped immediatly in a go second team? 

I am in gold 3 now (it has gotten easier this last few days) and everyone except me has serris it seems

 I totally get where you are coming from with counterattack and slow champs btw, i just havent been lucky enough to pull one (i want one for CB)

Yes,  The  enemy  will  try  to  strip  the  Shield  +  Land  Def  Down.

This  is  why  you  want  the  whole  team  to  have  High  Resistance.

Than  you  will  use  Rhazin  90  Resist  Aura  to  stack  on  top .