Am attack reduction player so playing Montana or Uppers is great for me, but am planing to get one more deck. I would like stop bonus deck Nightmare or Piranas but am not so sure which one to pick. I will buy card so i can make good td, elo and survivor deck with few replacement cards. What is your suggestion ?
With nightmares Ghumbo Oshitsune and Kolos are banned in elo full time and i will get big penalty in td for them also . Piranas on the other hand are somehow limited in ability
Personally I would go for Piranas
and I don't even use their pillz manipulation ability because I don't like it (except for Selma)
I usually choose: Tula, Tyd, Ulrich, Taljion, Ector (never use Baba, but I guess he is also ok)
for 4 and 5 stars I choose colridge, Raeth and Kristin (of course Scubb is also hard to resist) and Selma
they have selection of cards which suit your playstyle
if you want to play with pillz manipulation, they got Hawkins, Hawkins Noel, Bonnie Ld, Smokey Cr, Scubb, sherly, Katan, dalhia and Selma
if you want a deck with solid card, Tyd, Ector, etc would suit you
of course Nightmare is good, but never really like them even for T2
maybe because I think azgorth is just another Tyd with ability
or Pan is heal which cannot reduce opp life (unlike Ector thus less chance for KO)
or because Glorg has too low power (and none of their 4 stars good enough except Oshitsune which banned and Azel)
or because Karrion is the only decent 5 stars in ELO and his ability is same with Azel (one of few ok 4 stars for Nightmare) which means you cannot use both in your deck
As alot of users have already explained, they both are very good when used correctly and in the right format.
Nightmare has and will always be my personal favorite, but I'm currently playing Piranas to change it up.
The best choice is irrelevant, just make two good decks with both clans.
Hope that helped