Defeating Sapphiron and Kel'Thuzad in the Frostwyrm Lair opens their heroic mode variants. As what is likely your final set of battles in the Curse of Naxxramas Hearthstone expansion, these aren't easy. In fact, even the Paladin class challenge in Frostwyrm Lair feels like one of the most difficult battles in the entire expansion, so you can imagine the heroic mode battles against Sapphiron and Kel'Thuzad won’t be easy.

In most heroic mode fights, the main changes are the health of the boss (generally moving from 30 to 45) and some buff to its hero power. While that's also the case with Sapphiron and Kel'Thuzad, there are some special aspects to their battles that make them a bit different than most of the previous heroic mode fights. If you haven't already, make sure to read our normal mode strategies for Sapphiron and Kel'Thuzad. While the heroic battle is a bit different, many of the same strategies can be applied and will be referenced.

Sapphiron

Heroic mode Sapphiron jumps from 30 health to 45 health, while its hero power doesn't change at all. Unfortunately, the biggest change is the lack of a Frozen Champion to protect your minions. That's right, unless you can freeze your minions at the end of your turn, they will be destroyed by Sapphiron as soon as its hero power is used. This makes the Mage a good class for this battle because it has several spells that can freeze any target, including its own minions.

Whether you want to use a Mage or not, you’ll need to fill your deck with charge cards. You need to be able to inflict damage as soon as you drop your cards, or use direct damage spells and abilities. Low-cost charge minions are your best bet, but classes such as Hunter or Mage who have good direct damage attacks also work well. A Priest with Shadowform or aggro deck Warriors are also effective in this battle.

Keep in mind that in addition to direct damage, you also need to be able to remove Sapphiron's minions from the battlefield. Mage and Priest once again work very well, while Shaman has a tough fight here due to his near useless hero power (all of his totems will be destroyed unless frozen). Whichever hero you decide on, do not put Alexstrasza in your deck. It will be destroyed before you can do anything with it should you attempt to play the minion.

Kel'Thuzad

Kel'Thuzad is a troublesome battle in heroic mode. Like most heroic mode battles, his health moves from 30 to 45, but his hero powers become a bit better. His phase one power now inflicts three damage instead of two, and his phase two power allows him to permanently control one of your minions (luckily it still costs him eight mana). If that weren't enough, he starts the game with 20 points of armor instead of 10, and when he transitions from phase one to phase two, his Guardian of Icecrown minions are now 5/5 taunts instead of 3/3.

That's a lot to deal with, but it's certainly not insurmountable. The first order of business is to clear away Kel'Thuzad's armor. Your best bet is to use low-cost minions and let the damage add up. Direct damage spells and abilities also work well here. There aren't a lot of big damage low-cost cards, so rely on playing multiple low-cost minions each turn and letting the damage add up.

Be ready for Kel'Thuzad's Abomination minions, as their Deathrattle can be a pain to deal with. If you have a way to silence (Ironbeak Owl), have it waiting and ready for the Abomination minions to avoid their Deathrattle. When you almost have the armor removed, remember that your turn ends as soon as Kel'Thuzad's armor is gone. Be sure you're ready for the turn to be over (you've played everything you can on that turn) before you remove his last bit of armor.

Once you reach turn six, watch out for Blizzard, and when you get to turn eight, you must be aware of Twisting Nether. Blizzard inflicts two damage to all enemy minions and freezes them, while Nether simply destroys all minions. Do not overplay your hand by having a ton of minions in play after turn six. Kel'Thuzad will use Twisting Nether on or around turn eight, and you will lose every minion in play when that happens. Cards with good Deathrattles work well at this point, especially Stalagg and Feugen so you can gain access to Thaddius. You can also play Loatheb to delay the use of Twisting Nether or Blizzard by one turn.

If you defeat all of the heroic mode bosses, you are rewarded with a new card back exclusive to the Curse of Naxxramas expansion. Consider it a badge of honor for rising to the challenge and defeating all of the bosses.

If you need tips or strategies to defeat the other heroic mode bosses or anything else in the Curse of Naxxramas, be sure to check out our game hub!