This is the New Card Barnes that will be released with the new adventure One Night in Karazhan. It’s a legendary, so as you’d hope it has a pretty cool effect.
It’s a neutral card so you can include it in any class deck. The Battlecry reads: Summon a 1/1 copy of a random minion in your deck.
Thinking of the best possibilities here, you could have an extra Ragnaros, Archmage Antonidas, Tirion Fordring, etc.
Thinking of the worst possibilities you could summon a minion that doesn’t do anything, like a Totem Golem, King’s Elekk, Faceless Summoner, any card that doesn’t do anything other than have a 1/1 body basically.
This is a great card though. The stats aren’t bad for 4 mana, and the chance of an upside is huge. I see this being played in a lot of decks.