When me and my group encountered these guys they were 4 or 6 blackguards all grouped together and they were "Level 16 ^^ Epic x2". Not as terrible as it sounds though, I soloed one of them as a lvl 17 enchanter because our tank failed to notice I had aggro. They are positioned on the sides in the same room as Lord Ree. I believe you have to kill them otherwise Lord Ree won't become killable.
On a more personal note: These are THE coolest guys I've ever seen, they are large, mean, wear fulginate armour and chop with a two-handed sword, what's there not to like about them!?
I might try to duo them with my bruiser if I can find a priest who can help me.