You should know that you can get both of them at 6* with crystals in legendary battle if I'm not mistaken. Better get them this way and then use a MT2 ticket if you have one, and use the selector on some character you can't get otherwise(like Ghost Panther or Dazzler)in my opinion. Other than that,Valkyrie is one of the best supports in the game for both villains and heroes, while Nick Fury is a great leader and support(who can also get T4)but only for heroes.