Well, I've just had a NASTY Orthus Experience. After he spawned, south of my Neighbour (who was between me and him), he wiped them out. It was over several turns and to be honest, I completely forgot he was around. My nearest city wasn't too lightly defended, I had 1 well promoted Warrior (Def/Combat 2/+40% vs. Melee), a second Warrior and a Wood Golem. The moment I saw Orthus I also sent two other Warriors (Def/Combat 2 and Combat 1/+40% vs. Melee/+40% vs. Orcs) to reinforce the city.
All the while the barbs had been slinging at me constantly. I had set it to Raging Barbs but the numbers I was facing astounded me, I had never seen so many before, but that's off topic.
Anyway, Orthus shows up by my city gates with Commando and Combat 5, at full health (it seems my neighbour put up a fight and or thus benefited from it). Because my roads were pillaged, my reinforcements didn't arrive until he'd taken out my Wood Golem and my Def/Combat 2 Warrior. He then proceeded to pick off my guys one by one. I'm not sure if he got a promotion in between but my units only got him down to half health by the end of it. That's one city raised.
Then, Orthus turned his eye to my other (non-capital) city, which was lightly defended because my reinforcements from that city had abandoned it to protect the (now raised) other city. Obviously, I couldn't put up much of a fight, and it got taken with ease.
I'm still actually in the game right now, and I'm not sure what his next move will be. He's between me and the Clan of Embers. If he's still allied with the Clan of Embers, then I guess my Capital will be his next destination, if not, then he'll probably go visit the Clan (who'll probably beat him now that he's a little weakened). Either way, he's done enough to cripple me completely and on all sides, except for the Clan of Embers, I'm surrounded by Barb cities and the subsequent barbs pouring out of them (I assume he has at least 4 cities, my one, two of my neighbours and another one that appears to be natural [and holds the dragon, urgh]).
The difficulty is (only) Prince and on Raging Barbs (with 0.23A installed), and whilst I certainly believe a better player in my position couldve handled him, I was, in all honesty just not prepared to deal with him. Until he showed up at my borders I had forgotten about him. My defensive forces were enough for the constant stream of barbs but they couldn't stand up to the might of Orthus.
So, all in all, Orthus has eliminated one civ and crippled my own to the point of no return, which is basically two civs fallen to the might of Orthus
I admit, this is the first time this has ever happened to me with Orthus (although I have seen him eliminate civs before), but it's enough to make me respect him. I don't think I'll ever doubt his power from now on. He's king of the barbs for a reason
/goes off to pick up the bloodied leftovers of his dwarf army.