Nefarian Heroic C’Thun Priest

The Control C’Thun Priest has everything needed to beat this difficult boss.  Priest has several options to deal with both big and small minions.

Nefarian/Onyxia 101

Nefarian’s deck contains Dragon Egg , Soulfire, Twilight Whelp, lava  Blackwing Technician, Dragonkin Sorcerer , Shadowflame, Twilight Drake, Dragon's Breath, Volcanic Drake  and the very difficult Drakonid Crusher

Nefarian’s power is to make two bone construct.  Onyxia’s power is to “rain” either 1, 2 or 3 hits on your hero directly.

C’Thun Mulligan Guide

No contest here, grab Northshire Cleric,  Beckoner of Evil and possibly a Power Word: Shield.  In the unlucky event he attacks your first card played with his Soulfire  4, you still will have another Northshire Cleric in the deck.   Drawing early is a huge advantage against a deck with 0 card draw and a few discard functions.

C’Thun Draw Mechanics

Northshire Cleric plus Power Word: Shield allows for low level kill / heal combos.  Loot Hoarder is capable of taking out one of Nefarian’s 4-2 minions and Acolyte of Pain can add for multiple card draws.  Although not a draw mechanic, the two Entombs allow for padding for a long game.

C’Thun Heal Mechanics

For those new to C’Thun Priest decks, there is plenty of synergy between Northshire Cleric, Hooded Acolyte, Priest of the Feast, Holy Nova and the powerful Twilight Darkmender.

Strategy 

Nefarian has 60 health (30 plus 30 armor).  Control the board and build your best weapon C'Thun early.  Only play C'Thun when he can survive the next hit.  Ideally, Nefarian plays cards early and not his annoying 4-2 minions, starving Onyxia of cards.  The added benefit is he plays  Power Overwhelming which destroys his own minion.  If you can time it, Sylvanas is perfect to play before you beat Onyxia if she has minions on the board.

Additional note: If you have it, Harrison Jones is an awesome idea for when you take Nefarian’s final armor.  Be aware that you will draw 6 cards, so be very careful where your C'Thun card is before you play it!