From chest we got Amorphous Selrach's Boots.
Some strat. The waves are not mezzable, but they are snare/rootable. they do summon. So we pushed one away, and focused on one at a time with an enchanter tanking. With the first boss (book) we killed it slowly, and as 3 adds spawned, we killed the adds. Then killed the first boss. A second boss spawned, and we finished off the third add, and then focused on it. We saved burns for under 50% health, and ignored the adds, which despawned when he died.