The rule is simple if the card share the same trial...(Beastman, Light Warrior, Empire and primals, they get +1 each time one of that card is in the battlefield)

Simple right? lets try beastman, the reason Is simple, they are the only 1 star deck you can have, until you get 60 cards.

There are 5 beastman 1star Card.. ¿Easy to get? its RNG

You will need 4 of this card, it could work with 3, but if you can get 4 is better.

Amalj'aa Silver Triad Card, Memeroon MUST HAVE!!!
Ixal Silver Triad Card, Jonas of the Three Spades, Joellaut
Sylph Silver Triad Card, Maisenta
Kobold Silver Triad Card (hard to get...)
Sahagin Sastasha, Sastasha HM (HM have better drop%.. or maybe I was lucky)