Duelyst 2
is a hard game to play and especially to get into. New players can be intimidated by the multiple barriers present to truly pick up this game; barriers like unintuitive game mechanics, small playerbase and overall lack of new player resources both in game and out.
One of these new player barriers is a lack of direction for collection building. With so many cards and mechanics that at times seem to have no consistency between each other, it can be hard to find a stable starting point and branching out from there. Even the typical new player strategy of playing whatever looks cool can lead to a lot of frustration such as attempting to create the infamous backstab deck.
Pre made decks, or Structure Decks, can alleviate
Duelyst 2
's unique issues that come along with being in a unique genre. Structure Decks can not only give new players confidence in their decks but can serve as an example of what a
Duelyst
deck looks. They can also give casual players an extremely quick and easy way to know this game's feel and whether it's a fit for them.
In general, Structure Decks can be seen as an invisible hand, gently guiding player choice into a generally accepted set of principles establishing our common understanding of this game. Of course there are downsides to this, one of which is a suppression of creativity. Players can feel as if they are being forced away from all roads except the one in red lines, but this should only be taken as a warning against scope creep rather than an outright halt to the idea.
The new player onboarding experience in this game leaves much to be desired and I hope this suggestion will give you pause to consider the issue more deeply, starting with Structure Decks.
EDIT: I forgot to include suggestions on implementations. Sticking with low rarity cards makes the most sense when having a goal of preserving feelings of progress in your collection. But in cases of essentials being a higher rarity, the two paths forward are either adjusting said card's rarity or compensate other factions by giving them a legendary as well even if its a neutral legend rather than a faction.
Stay true to the unique gameplay patterns each faction offers rather than white washing them all with bog standard midrange. And solidify the experience by creating an achievement where once you play with all 6 structure decks, you can choose one to permanently own. That is, you will be given 3 copies of all cards in that deck.