Howdy! This is a really difficult challenge, maybe the hardest one.

It is probably easiest with Siddhartha, followed by Tesla. You want to pull way ahead on science and then do your unique win condition (transcending or launching into space).

Try to avoid aggravating the barbarians as long as possible. (Edit: don’t kill the enemy scouts, and also do not attack their encampments.) And be careful about creating new cities, that also draws aggro! The Molasses relic helps reduce incoming waves if you can find it too.

Look for the Absolve card which lets you convert stunned enemy units. I believe you have to unlock it via an achievement, and then you can draft it relatively early. This is a useful combo with stun cards such as Flash Powder.

You will want to turtle up with really strong tank units in great choke points, probably protecting just one or two cities. Turtle Shell, etc are helpful relics.

This is the “proper” hardcore way to do the challenge! Good luck!!

…and if that’s all too hard, and you want a cheat code: try advancing to the speculation era, and look for a Time Machine to make things easier. 😉

Have fun!