Here is what I do on Blue Champ.

For AoE Aggro control:

1. To begin with, you have to bunch all the mobs together. You cannot pick 1 mob, wait and go to next one, you have to run really fast and grab all your group is capable of, and hold them in 1 place.
2. While you are running to grab the adds, make sure there are no hots on you from the healer (you can tell them not to heal you while you are grabbing adds). Your passive reflect from Blue Line will also help you a bit while you are running to grab mobs. You can also use Horn of Champions while running for a ranged skill taunt, if there are lots of mobs stacked together.
3. Now that you have all the mobs stacked up in one place, stun them all from your Champ horn of Gondor and then use Battle Frenzy, then Raging Blades. Let your DPS people in your group get some nice hits on them. After you see your group has done some damage on them, (usually 2-3 seconds) – do Blade Wall.
4. Now depending on your group’s DPS, some mobs maybe are on them, some not. You have to check that yourself, if lots of mobs are on your DPS guys, the only way you can get them off is from True Heroics, that’s your AoE taunt, but it has a large coolown, so use it wisely. If your Horn of Champions is available, use it also.
5. Usually you can hold AoE aggro just from consistent Raging Blades – Blade Walls – Swift Blades, and well timed AoE horns, so you can get a nice burst of those AoE skills. But if your group’s AoE dps is too strong, then use True Heroics to grab all the mobs. This is why point 1 and 2 are important, try to grab all the mobs possible (to the capabilities of your group), bunch them up, and use Heroics when needed.

For single-target aggro control:

1. This aggro control is generally easy, but with a strong DPSer in your group (such as Red Burg), it can get messy.
2. You want to start the boss fight with Max Fervour (use Battle Frenzy pre-fight).
3. Start with Brutal Strikes – Clobber – Swift Blade – Wild Attack – Champion Challenge (taunt) – Battle Frenzy – Raging Blades.
4. ^ That’s your standard opening rotation for Bossses. Eventually you will lose aggro, so don’t forget to re-taunt when Champion Challenge comes off cooldown.
5. If your group’s DPS is too strong, and you lose aggro after your 1st taunt goes off, use True Heroics.
6. After 30s, when you see your aggro is set for the remainder of the fight, keep an eye for mechanics and use Cooldowns as necessary.
7. Sudden Defence and Adamant are your biggest and most reliable cooldowns, use them as required, if you get big hits, use Sudden Defence first, and if you are still taking a beating after that and your healer can’t keep up, use Adamant.
8. Always try to keep Bracing Attack on cooldown, it gives a nice buff of 15% incoming healing, which will help your healer.
9. Dire Need and Fight On are not effective cooldowns, but you can use them if you have nothing else left.
10. Try to keep Blade Wall and Horn of Champions as much as possible on cooldown also, it debuffs your target(s), which will help.
11. As for Unbreakable (the capstone trait of Blue Line) is just oddly designed, I find no practical use for it. I mostly just use it as a pre-fight buffing skill and use it when I’m starting a fight, and after that, just use on Cooldown.
12. Try to keep your Clobbers available for interrupts, we usually assign our tanks to be the first person to interrupt, for best practice.