What effects would occur if the mongols had invaded Sub-Saharan Africa?

Mongolia doesn't partake in that kind of thing. 

The same effect as if they invaded Antarctica.  They'd sit on their camels & say "What the F are we doing HERE?  This place blows dead bears.  Let's go invade Munich & down a few beers!"

We'll see.

They're doing it now.

Sound effects mostly, I'd imagine. Like "Giddy on, horse! Go! Let's get to Sub-Saharan Africa quickly! Mush!" and "Hey! This is taking a really long time, isn't it? And I'm really hot! Phew!". Naturally, that stuff would probably not have been said in English, but I can't speak Mongolian or whatever the fcuk other languages they really used. Hope this helped.

Time doesn't work that way. It's not like you time travel, step on a butterfly and suddenly Hitler is back to life.

Very tired horses.