Depends on what you're trying to build for.

FB, Sepulcher Sentinel, Khatun, and Scyl are all good choices, but it really depends on what your next target is going to be.

Scyll or warlord.

You also might consider bringing doompriest up to at least rank 5. Her passive is ridiculously useful.

Peydma Sycl  Coldheart

why is FB still at 40

WARLORD

What are you trying to beat next on your account?

It might have impact on who I pick to be your next 6 star. 😁

Doom  priest,  scyl  of  drakes  and  omg,  stag  knight.  Peydma  should  be  usefull  but you  already  have  Tayrell  For  A1  decrease  attack  50%.   Don't  bother  with  frozen  banshee  as  you  already  have  occult  brawler  and  the  posions  would  stack  over  the  10  debuff  limit.  Yeah  she  has  the  poison  sensitivity  debuff  but  you  might  not  even  get  that  off  when paired  with Occult  Brawler  in  clan  boss  fight  and  personally  i  tried  them  both  and  he  does more  dmg  on  clan  boss.  Although  it  depends  on  the  amount  of  other  debuffers  you  have.  Meaning  after  10  debuffs  your  locked  out  of  any  other  debuffs  like  decrease  attack.  Coldheart  is  a  must,  try  and  get  one  more.  For  clan  boss  you  may  need  pain  keeper  but  she  is  situational. legendary  are  mostly  a  given  due  to  their  base  stats.  Hope  that  helps.