Regarding Starranger's post, I just finished such a game last night. However I was loyal to Moro and he to Amelie till life/death do us part.
Playing as paladin with her resurrection skill and using black knights boosted by some of the important artifacts is
crazy powerful. There were only a few fights that caused me to pause and reconsider my strategy, e.g. suppression fights where gremlin towers kept casting sheep.
When I first extracted the Shard of darkness and had a relatively small number of black knights (perhaps some 80 of them) I remember thinking "Ah, so this is the KB:AP equivalent of the KB:TL Anga's Ruby + girl army". Then when I had almost 200 of them, this changed to "Okay, this strategy is definitely stronger than the one in TL" and finally at around 300 to "Grossly overpowered"
Anyhow, it was a whole lot of fun and I ended up breezing through a large chunk of the game attacking everything in sight without thinking twice about it - and this was on impossible, so this should give you some idea as to just how powerful this is. However, I will not do repeat this again soon as it would get stale fast, I'm sure.