I really like the "Alliance of Angels" sword (or something like that). It grants a prayer ability and allows you to combine creatures from any castles into one unit without morale penalties. It takes up a large number of slots. But here's the catch: the artifacts that are used to assemble it are MUCH more useful than the aforementioned sword.
Actually, the artifacts that are used to assemble it simply provide +21 to all skills, while the Alliance of Angels provides +21 to all skills + anti-racial discrimination + Call to Government!
The Alliance is definitely more useful...
