I Love the Smell of Saronite in the Morning (25 player)

When soloing the 25 man version this is currently the easiest way to get both achievements from General Vezax:

1. Clear all the adds in the room.
2. Pull General Vezax.
3. Do not interrupt his Searing Flames spell cast at any point in the fight. If left uninterrupted General Vazax will just stand there and cast it indefinitely. He won't even auto attack. Searing Flames was doing about 300 damage per cast to my 581 ilvl warrior.
4. At this point you can go afk for about 3 or 4 minutes while the Saronite Vapors spawn. Don't kill them.
5. Once enough Saronite Vapors have spawned they will form a Saronite Animus.
6. Kill Saronite Animus and then proceed to kill the boss.
7. Gratz with both achievements.

Note: General Vezax has a 10 minute berserk timer. Forming the Saronite Animus takes roughly 5 minutes.

Be aware that its the first 6 saronite vapors that you have to let merge. We accidently killed the first 2 and let 6 more spawn which did not merge. also no more spawn after that. we let boss hit enrage and wiped it up.
Completed the achievement by letting the first 6 merge without fault.

Kill General Vezax on the hard mode on heroic dificulty.

Vezax spawns a total of 6 Saronite Crystals over time. Killing these Saronite Crystals creates Saronite Vapors on the ground, which allow casters standing in them to regain mana to counter the effects of the permanently active Aura of Despair.
If no Crystals are destroyed, eventually 6 Crystals will be alive at the same time. These Crystals then merge to form the the add Saronite Animus. This add casts the stacking damaging debuff Profound Darkness on the raid and Vezax gains the immunity buff Void Barrier as long as this add is alive and stops casting Searing Flames.

Lack of mana regeneration means that caster DPS without functioning mana-regaining mechanics will have to make extensive use of the Shadow Crash buff and resort to wanding when not buffed. Healers will have to be very conservative with their mana to ensure they have enough left at the end to heal the massive AoE damage from the Saronite Animus.

This achievement requires the raid to kill this add before killing Vezax. Since Vezax is invulnerable as long as the add is alive, this seems like a sensible approach once the Saronite Animus has spawned. The entire raid being hit by increasing AoE damage while healers are running on fumes also makes it advisable to kill the Saronite Animus in a timely manner. Killing any Crystals before the 6th is spawned will make sure the Saronite Animus never spawns, as will killing Vezax before the 6th Crystal has spawned (though it is not likely this is possible).