I think it's easy if you have a well-built team even without the buffs.

Those with lower level pets who don't activate the seals (which would be me at the time I fought him *facegrounds*) will find him way more difficult.

However I did survive the battle. XD

You fought him after the nerf, with drastically overleveled pets. It makes sense that he was easy to take on. One will typically reach him during low level 40s in a regular playthrough, and without going and doing some serious shopping will likely still be down in level 25-30 gear. (I know when I got to him, personally, I'd yet to run into anything nicer than the level 25 epics I already had equipped.)