I'm trying to make a list of the staple cards in each clan. These cards are the best of all clans and should considered in all mono decks and most dual decks that uses that clans.
I'm gonna start off with Gheist since that's the clan I use almost the entire time. Feel free to comment, and put out what you call your staple cards.
**: Arkn and Z3r0 D34d all the way. Platinum and Elke are also good if you need more 2** (Elke being a good combo with Wardom)
***: Bristone and Leviatonn win this department. Dolly is a nice card, and you'll often have to use her since Bristone and Leviatonn get banned a lot. Luba gets my 4th spot on this category.
****: This one is hard with only 7 4star cards, 4 of them are really good. Draheera is a must in mono clans, he's probably the best card you have an almost automatic 6dmg. Toro and Methane are also really good (in that order) but they get banned a lot, you can also use Anibal as a nice revenge filler
*****: My favorite cards are the 5stars. You have a lot of options to play. I like Wardom the most, making him my staple 5***** everytime he's not banned, Rolph and xU52 are also great cards, Vladimir is the weakest and he's still a good so-so beginners card, but by far a staple. Lin Xia has an ability that's hard to use since you can't always get those -4 opp life, because of the minimum so I stay with the first 3.
6 staple cards that are a must in any mono Gheist deck I use, with some fillers. Take 4 and you have a nice dual. R&C