Cheap Giantfin Rogue Deck (Heroic Mode)

Strategy

Since Giantfin draws 2 additional cards on each turn, Mill is a natural strategy. Despite the fact that he has a 50-card deck, it is still comparatively easier to Mill him than a regular game in Constructed.

Mulligan for Backstab, Fan of Knives, Wild Pyromancer, and Coldlight Oracle, and simply aim to remove his board for as long as you can. Once you are able to play a Coldlight Oracle and cast either Gang Up or Shadowstep on it, you should do so, even if it does not Mill the opponent any cards. This is just to fill your own hand up on options to make sure you can continue to clear the opponent's board.

The overall goal is simply to play a board clear every turn and then eventually run your opponent out of cards. Although Giantfin is able to easily refill the board every turn, he has very few hard to remove minions. Murloc Warleader and Old Murk-Eye are the key targets for your removal like Eviscerate, while everything else can simply be cleaned up by any of your AoE effects, Vanish, or Wild Pyromancer.

Make sure to do the maths each turn once he starts approaching the end of his deck, and remember that at the start of his turn he will draw 3 additional fatigue cards taking additional damage. Using this information, it is very easy to kill Giantfin from even a very high health total.