(video courtesy of WTBBlue.com, an excellent up and coming website for WotLK guides and videos to 5-man, 10-man, and 25-man encounters. Go check it out for yourself!)
“Loken is the mastermind behind the war efforts of the iron dwarves of Northrend. Having previously served the Pantheon, he has recently heard the calls of the old god Yogg-Saron. Since that moment, he has lost all faith in the Titan’s vision and considers the Old God his new master.” – WoWWiki
The fight boils down to two main things you ought to look out for. The first is a raidwide aura that does periodic damage to all members that deals damage ever two seconds. The damage scales with the indivdual’s distance to the boss himself. Thus, you will want to stand really close to him, if not, on top of him.
The second, and perhaps the trickiest part of the fight is avoiding Loken’s Lightning Nova. On both modes, a raid emote will appear saying that Loken is preparing to cast Lightning Nova. During this window, you have FIVE seconds to move out of the nova’s twenty-yard range. Once the nova is cast, you must get back to Loken as quickly as possible, minimizing damage from the aura.
Mastering the Nova Dance
There are two general approaches to movement during the Lightning Nova. One involves the tank moving out of Nova range, and the other involves him or her staying behind and taking the full damage when the spell is cast. Tanks that move out of range should stay in place after the nova and simply let the boss move to him or her. The other members should move in the same direction as the tank to minimize their run distance post-Nova and receive less periodic damage.
The latter method is doable if the tank is well geared for the instance. The other members will not have to worry about movement direction, since Loken will stay in the same place the entire time.
Thus, blink is a godsend, since you travel the same distance as the nova itself. However, do not assume that you are automatically out of range after casting it, since the spell is not exactly perfect at the moment.
Pop all your cooldowns as soon as the fight starts, and when they’re up again, save them for after a Nova. This way, you will receive the benefits of the spell’s effects for longer periods of time, without being interrupted by having to run out of his Nova.
For some reason, my water elemental is immune to all periodic damage as well as Lightning Nova, so you don’t have to worry about him. Mirror Images die instantly, so don’t even bother using it.
Ice Barrier should be kept up whenever possible to both minimize damage as well as reduce the strain on your healer. Ice Block can save your butt in an instant if you are unable to get out of range. You should cast Cold Snap as soon as you come out of Ice Block, but be aware that due to Hypothermia, you will be unable to use Ice Block during the next Lightning Nova, so be prepared to Blink out.
You may opt to use Mage armor for the resistance against the periodic damage you’ll be taking. It is also quite useful if by any chance one or both of the other DPS classes die during the fight. If you have to shoulder the damage load by yourself, be prepared for a somewhat longer fight.
Ornate Wooden Stola – An excellent pre-T7 chest piece. Somewhat comparable to the Robes of Crackling Flame, but you sacrifice haste and MP5 for more crit. If you’re not yet at the hit cap at this point, you should go for the Ebonweave robe, but this is a good drop to take on the way there.
Flowing Sash of Order – The badge sash offers better stats overall, but this piece is a decent holdover until you accumulate enough emblems to grab one. The Spirit is a bit of a waste, though.
Woven Bracae Leggings – This is a truly excellent pair of pants for any cloth caster, even disc priests. There’s no reason why you shouldn’t pick this up, unless you need hit, or want T7 set bonuses.