So in another thread I put forward the idea of a Roman Empire that survived 1204, and then maintained/built upon their Ayyubid alliance to reclaim Cilicia and then Anatolia.
This was then followed up with the possibility of the Roman Empire becoming the Mediterranean equivalent of Moscovy - a peripheral enforcer Empire.
This has the advantage for the Romans of restoring almost all the Eastern Empire in a few decades (assuming a joint Roman-Mongol victory), but opens up the influences of the Pax Mongolica to the Roman Empire.
What cultural or economic impacts would there be of the Roman Empire being subservient to the Mongols, whose collective Empire is now from China, to Egypt and the Balkans, and Russia?
Vice versa as well, what could this Roman Empire give back to the Mongols in kind?