Cool. Thanks again.  

Though you are still an early game player, I'd put my focus on heroes, who are playable in ,many areas. Some mentioned heroes here are mainly usually in specific areas (e.g. Geomancer, Ultimate Galek).

I'd really recommend to build Deacon Armstrong first. Speed aura, tm control and aoe defence down are great anywhere.

I play him in any dungeon (lvl20+), in arena as well as in CB. He does great 👍

This is a bit inaccurate. Geo can be any level to have warmaster, as long as he is rank 6.

Thank you King and Riptide for your advice.  I really appreciate it.

Yes,  I  know.  By  'Level  60.'  I  meant  Rank  6.  It  is  pretty  obvious.  And  he  needs  to  have  Giant  Slayer,  not  Warmaster.  That  way  he  can  proc  damage  on  his  Passive  reflects,  building  up  his  main  way  of  damage.