
This card has a really cool effect, and other reviews describe ways to use this cool effect, but I would like to very clearly point out that this card also has a major disadvantage, which is that it is really expensive. What this card really does is to take one card in your hand, and convert it to three identical cards. Which means that, ultimately, you are spending 4 resources, 3 XP, a card, and an action, merely to draw two extra cards, which is an outrageously expensive way to draw extra cards. In return, you get the advantage of drawing a specific card (albeit one you must already have in your hand) rather than a random card.
What this means is that in order for this ally to be worthwhile, the card you place on it can't just be a nice card, it has to be a really, really super great card, so great that it is still a great card to play even if you increase the cost by a huge amount.
Now, to be fair, this isn’t the only thing you get for playing Dayana, as an ally she does have the advantage of soaking up damage for you. But then, she also has the disadvantage of eating up a very valuable ally slot, so this doesn't change the net calculation all that much, she still is mega-expensive for each "virtual card draw" she gives you.