Expand the empire North and speak to the Navajo people of the coming whites. Take boats and migrate fully to South Africa via boats taken from conquistadors and the like (I'm assuming this is sometime in the 15th or early 16th century.)

We leave the old world behind and set up our new land in parts of Africa uncolonised, having enough food to survive prior to the next harvest. Once we have a small string of well defended towns set up (All men are soldiers, Children and women do town work), we encourage reproduction to set up the population as fast as possible, and begin invading slave areas and freeing the slaves, giving them back their tribal culture while having them ally with us, we drive the whites out of mid Africa through constant annoyance and minor attacks, like a terrorist organisation.

Once we have established a large colony, we surround the border with waves of soldiers constantly on guard, slowly pushing forwards as we expand our turf. Once we've caught up in our technology based on developing from european secrets, we begin turning into a proper civilisation and develop laws, tax and government. We then invade smaller tribes and induct them into our growing strength, we later attack morocco through waves of invasion from thousands alongside our well matched technology. After taking Rabat (Assuming that was the capital at the time), we then copy the spaniards and fully westernise our nation. We then establish ourselves as a real threat through rigorous military drills and religious unity throughout the kingdom in the style of a military based belief in power. After taking advantage of the spaniards fear over us, we offer an alliance to France and both invade spain, sweeping through their countryside through heaps of storming in hordes and discipline.

We split Spain between the French, with the French taking the now 'North Spain' and the Great Aztecan Empire taking the Southern west side. After this treaty has been carried out, we then send waves of men to sail the mediterranean to the Ottoman empire. We then initiate the great storming of Constantinople. No Warnings, no Declarations, no reasons. We attack via sheer number and sweep through before the full army can arrive, and burn the city to the ground, ransacking the food for the return and the secrets of their technology. We also take survivors as slaves back to the nation and keep them in a massive prison complex in the North African Desert. They're bred, born and fed here and leave only when ordered as slaves by rich noblemen.

The Ottomans won't be able to cross the harsh desert without mastering surviving the harsh terrain, something their army will fall short in. After their capital is destroyed, and their army scattered, their conquest of Hungary will fail and their entire empire's structure will begin to collapse. It's at this point I allow both the western and eastern territories of Eurasia to have at the weakened superpower, each taking their own slice. Not only have I now set up a huge Slave Industry, but I've also established myself as a gentleman you do not screw with. I later purchase all of spain peacefully through influence over France built up over sturdy trust yet underlying fear of my swarms of disciplined religious warriors.

Now that I control a huge portion of the old world, I return to the new and blockade the ports of the British Colonies and spanish control over mexico with my Navy. I move in so fast the boats can't leave dock without being shot down. Now that I've cut off communication with the old world, I slowly rise up the new world, destroying the new colonies taking their first baby steps with ease. I burn it all to the ground and tell the Native American tribes that I have eradicated the White Man and now ask only for them to return with me to my great structure in the desert. I enslave the Americans through trickery and The Brits barely have time to establish a response. I remove any signs of my nation ever being there and decide to be extra careful by being on guard in case the English Declare war, they're my only threat at this point, but I make plans to deal with them alongside France.