Best Deck to Beat Grobbulus in Heroic Mode in Naxxramas Construct Quarter
Grobbulus in heroic mode has a hero ability that will do area of effect damage and then summon minions for all minions he killed. This means it is best not to play any minions into him and to stop the incoming damage. A good deck to beat Grobbulus in heroic mode is the normal form of Freeze Mage to stop the minions from attacking you and to set Grobbulus to 15 health in turn 9 and then kill Grobbulus in turn 10 and 11 using burn cards. The recommended deck to beat Grobbulus is shown below.
2x Ice Lance
2x Acolyte of Pain
2x Arcane Intellect
2x Frost Nova
2x Ice Barrier
2x Ice Block
2x Earthen Ring Farseer
2x Cone of Cold
2x Azure Drake
Best Strategy to Beat Grobbulus in Heroic Mode in Naxxramas Construct Quarter
Play Freeze Mage against Grobbulus in heroic mode as you would normally casting the delaying tactics like Frost Nova, Cone of Cold and Blizzard. During the other turns play the secrets to make it easier to stay alive. In turn 9 use Alextraza on Grobbulus to set Grobbulus to 15 health. Then in turn 10 and 11 use the burn like Pyroblast, Frostbolt, Fireball and Ice Lance to kill Grobbulus in heroic mode.
Note that it might take a few tries and a good starting hand to beat Grobbulus in heroic mode.