Easy to beat first boss of molten core, this should be a breeze if your prepared at all.

Abilities:

Impending Doom: Deals 2000 shadow damage to the afflicted target after 10 seconds, this is AoE cast onto your raid.

Lucifron's Curse: Increases cost of spells and abilities by 100% for 5 mins. This should be dispelled as fast as possible.

Dominate: Cast by Lucifron's guards. Make sure to purge this as fast as possible.

Pull:

When the path to Lucifron is clear have 2 hunters each pick on of Lucifron's guards and get ready to pull them. Your hunters will pull these 2 guards back to your off-tanks while your MT will grab Lucifron as he comes closer.

Fight:

Pull Lucifron into the corner a small ways away from the raid, kill both the guards first focus firing them down one at a time before working on Lucifron. Make sure that all healers get Lucifron's curse dispelled off of them else you will run out of mana.

Once both guards are down Lucifron is a breeze, beat him down and keep the dispelling up and you should win.

One trick to use in this fight is having casters watch the raid timer for the curses and jump out of range at the last second to avoid getting hit with it.