Tokugawa. I thought he was an isolationist, but dag....
In my last game, he, Isabella, Mansa Musa, and Stalin were on a continent shaped like the Kamchatka territory on a RISK board. Genghis was there to, but he was overrun by the Barbarian Uprising Event. Mansa Musa heads north, captures Karakorum from the Barbs, builds two cities- Gao in the south, near Stalin, and Djenne north of Stalin. Stalin DoWs, an captures Timbuktu and Gao. Mansa capitulates. Then, Tokugawa has a HUGE empire. At least 15 cities. He's spamming Settlers, and soon has the north east, central area, and west coast under his command. He fights border wars with everyone, taking Toledo, Santiago, Walata, and St Petersburg before peace is made. I was isolated, so when I found them and looked at the Foreign screen, it was all red lines. Insane!
Plus, Tokugawa was at Macemen while the others were still using Axes. He was teching and warring effectively. Of course, because of all that warring, me and Roosevelt, the tech leaders who were also isolated, had Caravels and Muskets.