Guide to Deathbringer Saurfang

Health:

• 10 Man - 8.785M
• 10 Man Heroic - 12.3M
• 25 Man - 31.86M
• 25 Man Heroic - 43.93M

Abilities:

• Blood Power - Saurfang grows 1% larger and deals 1% more damage for each point of Blood Power he has. Instant
• Blood Link - Saurfang gains Blood Power from damage he inflicts with abilities and summoned creatures. Instant
• Call Blood Beast - Saurfang calls forth 5 (2 in 10 man) blood beasts every 30 seconds
• Rune of Blood - Saurfang leeches health when he performs melee attacks on targets marked with Rune of Blood. Leeches 5100 to 6900 health from an enemy target and heals Saurfang for 5 times that amount (gains 1 Blood Power per hit)
• Boiling Blood - Boils the blood of an enemy, inflicting 9500 Physical damage every 3 sec for 24 sec, up to 6 players in 25 man (gains 1 Blood Power per tick)
• Blood Nova - Blood explodes outward from a random enemy target, inflicting 10000 Physical damage to nearby enemies. (gains 2 Blood Power per target hit)
• Mark of the Fallen Champion - Deathbringer Saurfang's melee attacks splash to the target, inflicting 3800 to 4200 additional Physical damage. If the target dies while under this effect Saurfang is healed for 5% of his total health. (20% in Heroic) This debuff is casted on a raid member each time Saurfang reaches 100 Blood Power. (gains 1 Blood Power per tick)
• Frenzy - Saurfang goes into a frenzy, increasing his attack speed by 30%. Instant (occurs at 25%)

Blood Beasts

• Resiliant Skin - The thick skin of this creature reduces damage from area effect attacks by 95% and damage from Diseases by 70%
• Scent of Blood - Saurfang's Blood Beasts catch the scent of blood, reducing all nearby enemies movement speed by 80% and increasing their damage by 300% for 10 seconds. (Heroic only)

The Fight:

Blood Power

The basis of the entire fight is Blood Power. Just about everything he does will build up it up, increasing his damage by 1% each time. This builds up to 100 and will be expended to perform...

Mark of the Fallen Champion

Thrown out on some random non-tank player, it does 4K ish damage per attack Saurfang himself does. So, basically a constant hard hitting DoT to deal with. And should they die, Saurfang will heal himself for 5% (Heroic: 20%).

So, keep them alive. Pally beacons work well to keep a constant heal on them. And should they die, do not battle rez them, the debuff persists after death til the fight is over so they'd just instantly die again and healing Saurfang.

Blood Beasts

Throughout the fight, Saurfang summons Blood Beasts, 5 in 25 man, 2 in 10 man. Every time they hit someone, Saurfang gains Blood Power, so ideally, they are not to be tanked but ranged dps'd down.

Also resistant to AoE and Diseases, so single target damage must be applied. Kite them, root them, stun them, snare them etc. Hope the ranged can burn them all down fast enough each round.

Heroic: They gain Scent of Blood which is a short range aoe debuff they put out on the raid, while gaining a 300% damage buff. That basically means they one shot anyone, including tanks, so stay away. The debuff also slows your movement speed, so would be very dangerous to kite if you get caught up in it. Basically all means, kite perfectly or you (and the raid) are probably dead.

Blood Nova

The last tricks he has are these, Blood Nova is a "bomb" type debuff on the raid. Ranged targeted only (with sufficient numbers), but basically the mechanic that makes sure your ranged spread out. They get targetted, they "blow up", hurt people around, and Saurfang gains 2 Blood Power for each additional person it hits.

Boiling Blood

A DoT on random people. Gains blood power through each tick. Heal through it.

Frenzy

And at 30%, increases attack speed by 30%. You gotta deal with more damage, and likely Blood Power gaining more rapidly. So, the final push, pop everything, burn him down and collect loots.

Not a lot of tricksy abilties and mechanics, just can be brutal on damage and healers (pending appropriate gear level).

Hard Mode Summary

The Blood Beasts can one shot anyone, including tanks. Stay away and kite. Also more Blood Power generation so likely looking at 5-6 marks on your first 25 man kill.