When we first went into the Sacellum West Wing, my Black Orc Tank was rank 12. In this wing trash mobs start to hit you hard, if you're lower rank then they are. The noteworthy ones are the Mawgut Bull ogres in there. They come single or in a pack of two. If your tank is low rank, you might want to consider a guard on him from an offtank to share the pain. Once you're the appropriate level, they won't pose much of a headache, but in the beginning they were.
There are three (and a half) bosses in the Sacellum West Wing:
Sebcraw the Discarded
Lorth Thunderbelly & Slorth Thunderbelly (brothers?)
Hoarfrost is the first boss in there, but IMO hes the hardest in the west wing. He got a freezing aura that does periodical damage which poses a threat at lower ranks. His room is also bugged, make sure the tank places him on even ground, or he might get stuck or reset. Not much to say about the other bosses, pie. The last boss, or should we say bosses, is a couple of brothers with large weaponry - looks cool, but i was expecting some bigass flamethrower action in there. Well, it was not like that... one of them also drops a green set item.
One more thing to mention about this dungeon: Mawgut Gnoblars know how to build traps! ;)
You'll also find Unok the Gladiator in this wing, you need to challenge for the Test of the Arena quest.