I've been playing around with adding Katrin the Shieldmaiden to my
Victor Heartstriker deck and have found that it's an extremely valuable
card. For a two resource cost card, the benefits of having Katrin out on the field of play are huge for a Victor deck or for any creature based deck.
Katrin's ability to add +2 health to any friendly ally can be a life saver and also turn a low cost ally into a real problem for any opponent. So far I've used a combination of Katrin and low cost creatures like Dirk Saber and Kristoffer Wyld effectively in ranked matches.
As a draw mechanic, Katrin serves as a great ally to play with the intent of combining with Wrath of the Forest, especially when playing against AOE decks or stall decks that wipe out all allies frequently. Wrath of the Forest's ability is that when an ally is killed, you draw a card. It also serves as armor with 1 damage mitigation, which is a great asset along with the draw mechanic.
Katrin is extremely useful in creature decks that use Aldon the Brave. Aldon gives your allies +1 attack on your turn, so Katrin is turned from a defensive card into an offensive card that is tough to kill.
I have two Katrin's in my Victor deck now and plan on keeping her in. I replaced a couple of my low cost creatures with her and have started playing with more of a focus on buffing the creatures I have and playing a strategic game.