I tried this card on a Jenny Barnes deck in SOLO Play on STANDARD difficulty. My idea was to stack his boosts with St. Huberts Key to get +2 willpower and intellect. Playing him though almost got me killed on the first scenarios of the Carcosa campaign. At first sight he may look playable, fun or even good, but believe me, he is BAD (considering the current card pool). Let me explain:
-He costs too much resources to play, wich makes it even more difficult to gather the 10 resources you need for his static boosts. This also means he is to expensive to effectively serve as a meat shield.
-He is waaaay to slow, specially on the early scenarios. Remember that you don't have Hot Streak from the start, so collecting the 14 resources you need to play him and get the boost will take forever, even if you are playing Jenny Barnes with Lone Wolf. Consider that you normally also have to expend resources playing other assets or boosting your skills with Hard Knocks or other talents.
-His trigger ability "Gain two resources" is not that bad on multi player, but in Solo play it's not very useful. Consider that on average you will be loosing one action per turn fighting enemies or resolving treacheries. If you then constantly use 1 action to gather 2 resources from Dario you will only have 1 action left to advance the game, meaning you will loose to the Agenda.
-There are too many better allies than him (Leo de Luca, Lola Santiago, Dr. Milan, Beat Cop, etc.) and there are many other easier ways to boost your intellect and willpower. The willpower stat is by the way not very important for rougues anyways (except for Sefina maybe) and you are better of boosting it with Talents like High Roller or Moxie.
-Even when I managed to stack this guy with St. Huberts Key, what he provides wasn't worth the enormous effort. By the time you have it all set up you would already have drawn Leo de Luca anyways, wich is a thousand times better. If you are going Jenny Barnes clue gatherer play Dr. Milan instead.
-With his wicked smile he tempts you not to use the 10 resources you have put on him for the static boosts. Soon enough you will find yourself not playing important cards or not overcommitting to important skill tests, just to keep him happy (charged with 10 resources). I warn you, the over commitment to this guy could mean your demise.
In conclusion/Summery:
His smile fair as spring, as to put him in your deck he draws you.
His tongue sharp and silvery, as to invest 14 resources on him he implores you.
Your stats he boosts, as he swears to adore you.
Though dues need be repaid, and the overcommitment will ruin you.
His slow set up will snare you in bonds, as the Agenda advances glowing’, a fire.
To gore and torment you, till the stars expire. XD