The first boss is easier when u got the lightning mob between the other two, but it doesn't really matter.
The second boss can be a huge rng bitch. Wait always till he buffed the cc immun buff on one of his minions before u start killing the 2nd/3rd/4th minion. Also stay focused on your pet healing.
The final boss u can kill a lot easier, choose Exhilaration instead of Spirit Bond like i have done. Use Deterrance and Exhilaration twice in the last phase, although save all your cooldowns for this phase.