I've  been  trying  to  get  graybeard  for  a  while  now  and  haven't  gotten  it.  Then  again  i  am  on  normal  mode  and  can't  unlock  hard  but  still.  I  am  new  to  this  and  need  tactics

The  below heroes  in  my  opinion are  the  best  rares  in  the  Campaign.

-  Conqueror

-  SpiritHost 

-  Bersker

-  Warmaiden 

-  Executioner

-  Diabolist 

The  below  heroes  in  my  opinion are  honorable  mention  rares  from  the  Campaign.

-  Valerie

-  Skull  Sworn

-  Templar

-  Hound  Spawn

You  might  wonder what  is  the  difference between  my  Best  Rares  vs.  Honorable  mention's.

Well  the  answer  is  Combo.

The  Best  Rares  are  the  best  individually  for  what  they  do.

The  Honorable  Mention  Rares  can  only  be  best  if  you  have  the  right  Combo  with  them.

Example:

Skull  Sworn  isn't a  great  hero  by  himself,  BUT  their  is  another  hero  who  is  Legendary that  can  Combo  with  him.

i

Skull  Lord  Var-Gall  is  Leggo

Skull  Sworn  is  Rare  which  is  more  like  the  baby.

Together  they  can  be  very  fun  combo.

Obviously,  if  you  don't own  Skull  Lord  Var-Gall,  you  miss  out  on  the  fun/awesomeness.

This  is  why  I  put  Skull  sworn  as  honorable  mention  vs.  one  of  the  best.

Early on these are the key few:

Spirithost (some arena/dungeon applications due to increase attack A2 and ally speed aura)

Warmaiden (defense down on a 3 turn cooldown when booked)

Greybeard is OK due to his crowd control A2. 

The reason why it's important to focus on just a few of these is you will be putting energy into trying to get these champions, then needing to invest in them (usually Spirithost to 40, Warmaiden to ~50 is a good play, if you go with them), and farm copies of them as books from Campaign. This takes time and energy, thus we need to be very focused on which ones we're actually looking to get, and invest in. 

While it's fun to have a list of champions that have some - often limited - applications, it's not very practical for an account looking to build out mostly 60s (specifically your starter who will be your campaign farmer), and wanting to do so efficiently. 

As for odds/RNG of finding champions in specific campaign content, you can find that in this thread: 

https://plarium.com/forum/en/raid-shadow-legends/674_game-discussion/619341_drop-rate-on-dungeon-rare--blue--heroes---executioner-particulary/

Id stick with 9-3 for warmaiden , 12-3 for exp and forget  campaign rares for the moment . 

You'll be getting them eventually for sure , since you still have to redo the entire campaign 3 times , farm some missions that will require X stage from X level and then running them again for stars . And by that time you will know which of these you actually want/need ! 

For me actually using a champ is the best way to know their value for you.  I get a lot of great advice from this forum but I often do not understand it until I actually put into action.  

If you have a chance use Kael as your farmer.  He has lasting value.  Apo is another rare with lasting value.