This is probably a Hunter world 1st, if isnt, to bad .P
If you know the boss you know this cant be soloed by a hunter withot bugging him so thats what I did:
Hit the boss once at least, so you can loot him after, and let your pet do the rest.
When he bubles he will start to heal himself and heres comes the bug. Run away from your pet to despawn him and run to boss. FD and call pet fast. This will make the boss reset for a second and loose all the buffs/debuffs.