Do you love Rexxar, but hate Barnes? Do you hate Paladins overrunning your board with their Murlocs and Dudes? This is your deck then. I climbed from 2400 to 25 in one day with this deck, and felt like a fresh deck for once. (Update hit rank 3 legend)
(Edit. Put back in Alleycat instead of second Secretkeeper seems less clunky)
Priest: Most common class on ladder right now so let's start. Duskbreaker can be soul crushing against anything with 3 or less health, so we want to look for cards that allow us to get past it.
Going first: Keep 1 drops (but only one and not Tracking), if you have a Beast one drop keep Crackling Razormaw as well. If you have Secret Keeper, keep Freezing Trap, and Snake Trap. Always keep Cloaked Huntress. If you have a turn 1 and 2 play, keep Eaglehorn Bow.
Going second: Keep 1 drops, Dire Mole and Secret Keeper are the best (if both, choose one based on whether you have Secrets in hand or Razormaw/Houndmaster) and keep Crackling Razormaw. If you have Secret Keeper keep any Secrets. If you have a one drop beast keep Houndmaster. If you have a 1 drop keep Eaglehorn Bow [/card] and [card]Cat Trick, and of course keep Cloaked Huntress.
Mage: Very pivotal match-up sometimes you win sometimes you lose.
Going first: Keep Dire Mole, Secret Keeper, keep Crackling Razormaw unless you have a Cat Trick or Secret Keeper + any secret. If you have Secret Keeper, keep Cat Trick, Venomstrike Trap, and Snake Trap. If you have a 1 drop and a Secret keep Lesser Emerald Spellstone, and Eaglehorn Bow.
Going Second: Same as first, but keep Eaglehorn Bow, and don't keep Crackling Razormaw unless you have a 1 drop Beast.
Paladin: Best matchup by far, free win against Murloc, EZ win against Dude. Snake Trap is the best card against Paladin so playing it on a board that your opponent needs to trade into will win you the game a lot of the time.
Going First: Snake Trap is godtier! Keep any 1 drops (up to 2), if you have a Beast 1 drop keep Crackling Razormaw as well. If you have Secret Keeper, keep Venomstrike Trap, and Cat Trick. If you have a 1 & 2 drop, keep Unleash the Hounds. Cloaked Huntress again is amazing.
Going Second: Snake trap! Keep any 1 drops (up to 2), if you have a Beast 1 drop keep Crackling Razormaw as well. If you have Secret Keeper, keep Venomstrike Trap. If you have a 1 drop and a Secret keep Lesser Emerald Spellstone. Cloaked Huntress MonkaS.
Going First: Keep 1 Spellbreaker. Keep Dire Mole, Secret Keeper[/card, keep [card]Crackling Razormaw. If you have Secret Keeper, keep Venomstrike Trap, Snake Trap and Freezing Trap. KEEP CLOAKED HUNTRESS!
Going Second: Spell Breaker!!! Keep Dire Mole, Secret Keeper, if you have a Beast 1 drop keep Crackling Razormaw as well. Keep Cat Trick and if you have Secret Keeper, keep Venomstrike Trap, Snake Trap and Freezing Trap. Lastly Cloaked Huntress.
These are the primary classes I played against, I don't have enough experience against the others to say what's good so I'm sorry, will update as I play more.
In general the greatest strength of this deck is using the right secrets to push a ton of face damage, so set up situations where your opponent has to activate those secrets. Don't be afraid of value trades, this deck will get there with the damage eventually.
2: Don't waste secrets by throwing them onto the board (i.e. Freezing Trap into a 1/1)
3: There isn't a lot of healing so whenever you hero power someone, they usually lose that health forever. Maximize those hero powers so you can eventually burn them out with Kill Command
Here's a video by kiwiinbacon playing the deck at legend.