Sure fire way and easy as hell
After reading through the comments and seeing what everyone else tried I decided to do tyrannus a different way.
1 resto sham 2 ele shams 1 moonkin 1 pally tank
I clump my guys on follow always! Trying to spread out and heal through ice damage is a no go. Itotally stop dps when any dps has the brand I just heal. I stop all healing if my healer gets the brand and just dps. I have no frost resist gear except the shammy tot. The key is to keep moving and when he calls for rimefang to blast someone this is when i hit my spread out formation. The blast only pos one guy I hit follow and rinse and repeat. I never used bloodlust or even wrath. My dps did pop my tank a few times but I managed to heal him up with riptide quick. Just try to keep away from frost patches that are clumped together so when you get a rimefang call to blast a party member you can spread out enough to not take ice patch damage. They do despawn after about 30 secs so you can basically kite him between two areas. I found that standing by the exit will result in aggo from cave mobs and a quick repair bill. Don't worry about kiting him when he gets his powershot might ability, he did minimal damage to my tank when I even got hit. Spreading the team out when the dam iceblast from the dragon hits was what worked for me. The fact I have over a 25k gear score combined for my team probably helped a ton too! I got a beheader and some palebone snowshoes for my moonkin on my first kill tonight. This guy is an absolute joke on normal mode and I don't even move but heroicdid toss a wrench in the works. I am glad that Tyrannus does not have some aoe cleave attack or god that would be hell!
edit: This is even easier
I clump my guys to the left of tyrannus and pop my tots. I engage him with pally about 30-35 yards from group so when he knocks back im still in front of my group so I can dps. I have done this using all cd's and have done this using no cd's at all. Dps him constantly and watch your toon for the brand I spam healing wave on tank when any dps has brand and just continue. Tyrannus can never out dps my 20k heals from shammy anyway. If healer gets brand I just stop healing and basically thats it. I never move my guys even for the target ice attack that does aoe damage I just pop one chain heal after that and its back to dps. The only thing that can wipe me doing it this way is if the dragon puts down too many frost patches in the immediate vicinity surrounding my slave group and then slams a patch down right on top of them. I'd say 80% of the time I never move my slaves ever and the ice patch never lands on them at all.
