Nature for Slaking and Feraligatr

[Nm3k]

I've got two questions concerning natures:
1. Should I train a Slakoth with the Careful nature (Raise Sp. Def., Lower Sp.Attk) or with the Adamant nature (Raise Attack, Lower Sp.Attk).
2. And if I wanna train a Feraligatr with a nature that raise Sp.Attk, which one should I choose?

Thanks!

[Ironshell Blastoise]

1-Make Slaking Adamant
2-Make Feraligatr Adamant. He sucks my left nut if he's a Special user.

@leftovers
-Swords Dance
-Ancient Power
-Earthquake
-Rest/Protect/Surf