My showdown with Genghis Khan is inevitable, and should happen as early as possible.
Unlike Alex, who is now bothered by Cathy and Bismark, Khan does not really have any enemy, and he only has two neighbors - Alex and me. Alex is Khan's best friend; together they own more than half of the world's army. If I let Khan take Mansa Musa's land, he will be even more powerful. On the other hand, while most of Khan's spare army is bugged down by Mansa Musa's skirmishers, his homeland will be relatively defenseless.
Since deity AI builds up troop quickly and massively, I can't rely on a few Arnold axemen and catapults. I must capitalize on a military tech lead. My next bet is naturally maceman + catapult.
My research route is:
... Alphabat -> Literature -> Drama -> Music -> Code of Law -> Construction -> Metal Casting -> Machinery -> Civil Service.
I get Construction early, so most of my cities were producing catapults when I am shoot straight towards the maceman techs. Since Khan is 100% on war, I should be able to rush out maceman before Khan gets Feudalism (longbowman).
A good thing is that Khan does not have horse, so he does not have his special light horse archers. I don't need to spend a lot of extra resources on otherwise pretty useless spearmen.
As I was on my way to Civil Service, Khan's endless supply of army cracked open Mansa Musa's capital, leaving the African King only 1 poor city. In a few turns Mansa Musa will be finished, and Khan will have his full strength focused on me.
At this point, my army strength has been built up to be slightly higher than Khan's. Deity Khan is surely producing troops like crazy, but so do I. I dedicated Shanghai, Delhi, Bombay and Guangzhou for troop production.
I know my troops are more advanced and effective at city attacks, as I have a few war elephants, 6 catapults, and a legion of fine axemen ready to crack open any bombarded gate. I am also producing the Chinese special units, Cho-ko-Nu. (The inventer, Zhu-ge Liang, is spelld "Cho-ko" here. Basically it is a semi-automatic crossbow firing at short intervals.)
Should I declare war early, before Mansa is finished?
As my main army has been assembled at the gate, I decided to declare war about 10 turns earlier. Here is my battle plan:
(1) The only frontline city of Khan, Seville, was taken from Isabella ~500 years earlier. My cultural border is right adjacent Seville, so I can grab this town in a surprise attack, with a quick bombardment of catapult and axeman/elephant rush. Usually, 7 catapults is required to kill the entire defense bonus in one turn, while 6 catapults will take down a 50% defense to a negligible 5%.
From Seville, I will make a holding in the forest hill to the north, to wait for more reinforcement to arrive, and kill off any Khan's couterattack forces trying to reclaim Seville. In the above picture, you can see how much "backup forces" is waiting in Khan's capital. They will surely come out, and if they dare to attack me on a forest hill...
(2) After Khan's massive counter attack is neutralized, I will leave about 1/3 backup/wounded army to defend Seville, and dispatch the rest 2/3, self-healing elite Arnold forces to take Turfan, which is only 2-3 turns Northeast from my holding ground. This way, I can secure my capital, Shanghai, and have a close shot at Khan's capital.
(3) With Turfan in the bag, my Civil Service should be done, and I can slide back to 0% research, to save some quick money for maceman upgrades. Khan's capital will be tough as it is clearly a production city, so I will wait till I get at least 2-3 maceman. (Can't wait too long. Each maceman will take 235G, roughly 1.5 turns of income.) I've squeezed out all of my friends's cash just to get Civil Service done early. (At Pleased, AIs will give you free cash - but never Mansa Musa, the most stingy man in the world. According to what I read, however, Mansa Musa is actually a super generous King!)
(4) After healing and upgrades are done in Turfan, I will proceed to Khan's capital, Karakorum. There is an iron mine just outside the capital, and it is actually Khan's only copper/iron. I will camp my army right there, bombard the defense to 5%, and assult with my then-healed Arnold maceman and elephant.
(5) The war is essentially won if I can take Khan's capital. The rest would be just cleanup action. Khan has another city to the south, as well as Mansa Musa's capital in the far southwest. Napoleon will probably take care of that one for me, though.
In the meantime, I have organized a secondary army around Barcelona, Munich and Macau, just for defense purpose. I camp them on hills, forest, any strategic locations which also attract enemy's attentions.
The plans are made, and I declared war. I got another -1 "you declared war to our friend!" from almost everybody, but that's OK. I am still popular among the other AIs. I probably can't afford another, though.
After declaring war and taking down Seville, I shopped around for possible allies. Elizebeth and Saladin are all red-outs, which is not suprising. (Liz is only Pleased with me, and Saladin, although Friendly to me, is Pleased with Khan.) However, Napoleon readily offers to attack his good friend Khan with a cheap price. Mansa Musa's archrival is helping him to defend this time, huh?
With the French warhead on my side, I am much more confident about this war.
Everything goes as expected. Genghis Khan has organized a counter-attack force, heading straight to Seville. I camped my entire force on a forest hill. My only weakness I find is the copper mine on the hill, west of Seville. If the AI is smart enough to move its entire counter-attack stack there, then I will be forced to either abandon Seville (to take it back the next turn), or retreat all of my army back to Seville to defend, and lose my defense bonus). I think the former option is actually better, as Seville is not a valuable city.
The AI isn't so smart, it turned out. Khan wasted all of his swordsmen on my monster stack with 75% defense bonus. After realizing he can't make it with the rest of his stack, he marched a few miserable axemen and spearmen to both sides, trying to pillage the farm and the copper mine accessible from Seville. These suckers never had a chance, though.
With Khan's counter attack gone, I know I have a few turns of freedom here. My elite assault army marched northeast and tookdown Turfan with ease.
Finally, I got Civil Service. My best Arnold axeman is formally upgraded! (just look at that monster unit).
While my Arnold axemen are waiting for upgrades in Seville, I camped my elephants, regular axemen, archers, catapults, and one archer unit on the nearby hill close to Khan's capital. Hopefully, I can attract all of Khan's incoming units, to commit suicidal uphill assaults. Khan's capital, which has a Heroic Epic, is producing 1 swordsman every turn -- and this is a Marathon game! Crazy Deity AI.
Khan took my bait. He threw away all of his fresh, spare units from his capital to my stack on the hill. However, it suprised me when I saw elephants rushing out of his capital, instead of swordsman. I didn't know Khan had elephants... although my own elephant kicked his elephant down the slope. I don't bring elephants for no reason, you see.
Shown in the above picture (upper middle), Khan actually managed to settle a new city RIGHT ON an elephant herd, just after our war broke out. This location was previously occupied by one of Mansa Musa's city (razed by Alexander).
Since the city is right on the resource, I can't even pillage the camp. Fortuantely, Napoleon is here to help me. In the next few turns, Napoleon's swords and horse archers thinned down the city's defense, and my secondary army easily took this ill-fated utility city. No more elephants for Khan! War har har.
Without elephant and iron, Khan's days are counted. He made a suicide bomber (catapult), but 1 catapult is far from 6.
Even Mansa Musa managed to sneak 2 skirmishers to his back (sailing around half of the old continent!). Besides pillaging a village, Mansa's skirmishers probably attracted some of Khan's units, and lowered their health. That's great of you, Mansa! (Considering somebody who is down to their last crap city.) With the help of Mansa, my assault force was able to crack open Karakorum the next turn.
Khan is doomed. He asked for peace, but hell no. All of my productions are back to city infrastructure; I switched to Bureaucracy, and watch my stack of death eat Khan's last city alive.
Napoleon indeed took care of Khan's southern city, formerly Mansa Musa's capital. I am sure Napoleon won't return the city to Mansa Musa. He tried twice to grab it in the last 3000 years, both failed. Ironically he got it by attacking Mansa Musa's enemy.
I was planning to return Mansa Musa's capital to him, and converted him back to Buddhism, as Mansa Musa can help me block off Napoleon. Mansa's silly AI converted to Hindu as soon as he lost his capital, because his only city left has nothing but Hindu. Now, all hope seems lost to Mansa Musa. The only favor I can do for him is to give him a Buddhist missionary, so at least he can die a Buddhist, and a friend (thus giving whoever killed him a "-1 You declared war to our friend!" with everybody else

).
Bismark is not doing too bad against Alex. He lost his Monty city, but also managed to ambush one of Alex's cities in the north. Alex took his lost city back quickly. In this little clash, you can say that Alex gained 2 cities with nothing, and lost 1 city with everything.
Catherine is holding off Alex quite effectively, taking Philadelphia (a small town in the tundra north), as Alex can't concentrate on her entirely. Alex's new frontline cities, New York and Washington, are also poorly defended. New York is on constant revolt, but I never see it flip to Cathy after the war. (It flipped before the war, and Alex took it back after.) Probably Alex took it right back after every flip? Anyways, Alex and Cathy are about balanced now - I like it this way.
With one Deity Civ after another cracking out tons of elephants and catapults, I no longer holds a decisive military advantage. My 3rd wave of expansion is now complete -- Grenadiers will be the next.
With a total of 16 cities, I will enter another building period, to solidify my economy with harbors, forges, markets, grocers and well-built improvement. I will Hindu rush a lot of cities in the world, so Alex will be willing to convert to it, and become everyone's hate boy. Cathy will probably be the next hate girl. I will befriend Liz and Saladin, who are totally unlikely to backstab a friend, and are generally weak as well. Napoleon will become my ally in any future war, as now I know he is willing to take bribe from a friend to beat another friend's crap out.
The game is mostly in the bag now.
