P.S. I have no more of defence/hp affinities rares that I upgraded 

Shaman  isn't  a  Tank.

Shaman  is  the  Revive  Hero.

You  never  want  the  Revive  Hero  to  be  the  tank.

The  Reviver  Job  is  to  stay  alive  and  bring  back  the  tank  if  the  tank  dies  in  battle.

Jizoh  is  a  Tank.

Jizoh  is  a  Great  Tank.

Jizoh  is  Spirit  Affinity.

You  need  to  find  Force  Affinity  &  Magic  Affinity  Tanks  as  well.

Exactly. The problem is I have no good defence sets and ice golem drops useless counterattack sets instead of defence sets all the time

this game is not like other games you have played. 

your thick skin tank may be the last one to be killed. you no way to defend attack all skill (you may absorb a little damage but can't block it with a tank)

forget tank in pvp. 

How much HP does your Kael or Shaman have? Your Main Tank should have at least 10000 HP more than them. Do you have any more viable options than Jizoh? If not, stick Jizoh in a Retaliation Set and Immortal Set. That should boost his HP and make his chance of counterattacking even higher.

Another option would be Lifesteal and Immortal/Divine Life

I am farming defence for jizoh/ironhide, am sticking to defence, and I have an elhain. Fun fact my first ancient was a galek

This guy is so early game he should just be using 4 piece lifesteal on his champs and crushing through what he is working on.

update. I have jizoh as my tank now, working on ironhide.

Dark  S.  Statement isn't  really  correct.

You  want  the  Tank  to  have  lower  HP  vs.  Rest  of  team

-  Low  HP  vs.  Rest  of  Team

-  High  DEF  vs.  Rest  of  Team

The  game  targets  based  on  Affinity.

The  game  2nd level  of  targetting  is  based  on  HP  Levels.

The  game  3rd  level  of  targetting  is  based  on  BUFF's on  heroes.