Great cheap ally provides 2 thwart, and possibilty to flip if there is a bad situation with minion. Two points of life is small, but nothing will be "wasted", and even when using to second thwart is effective play. Guardian trait is not the most developed trait, but got some great stuff to coordinate with Eros.

My rating (A-C) is A- card worth consider in every deck

outside of confuse-lock decks, this is arguably the best 2-cost justice ally as of cycle 10. great for 2 thwart and a block. the confuse (easily achievable with power of justice) is just icing on a cake. in fact, even in confuse lock decks, i'd also recommend bringing eros. solid a-tier justice ally and arguably s-tier in certain decks. even though hes a guardian, he can be easily splashed into any other team for low-cost thwarting.