Ashling brings together sacrifice synergies, enters abilities, and traditional kindred payoffs into a single strategy
The flexibility of being able to choose a value for X is great because we might have an early-game case of wanting (or needing) to cast it for X of one or two, or we can wait until late-game and sweep a much bigger battlefield
Once played, the controller (the player who cast it) chooses one other player to defend this card
So this is clearly designed for one deck archetype, Life Gain, which is the third biggest archetype ever played, and it makes sense in +1/+1 counter decks that have the occasional lifelink dork or Commander or something that gains you life here and there like Akoum Refuge, and then if you have a Selesnya colored power matters build this would help there with things like Anthem effects
I've been wondering about her second ability
11 Tradeable Game Cards will be found on the Shadowless packs, and 11 ADDITIONAL GAME CARDS is found on the Unlimited packs