What are the most difficult settings?

I can win consistently on deity and would like a further challenge that is not speed runs. I want to play the hardest possible game to win against the AI within some limitations. It would perhaps also be a fun exercise in thinking about the difficulty of different settings.

Limitations:
- It should be a script and not an individual map or scenario
- No mods.
- All victory options enabled.
- BNW
- Not OCC, not Venice
- Max 10 opponents
- Speed Standard

My first idea is India in a duel size sparse tundra against all the warmongers. Other ideas?

Small map with 9 Shakas....use really advanced setup and turn on always war.

^ why don't we try tiny

Two self-created challenges:

Delayed Game
Delete your exploration unit, so you just have a settler.
Wait 30 turns without moving, though you can flee from barbarians if needed.
Then being game as normal.

Anarchy
Activate "save policies" allowed.
You're not allowed to buy policies till the Renaissance era.

Ascetism
You can't improve luxuries.

In fact playing on map with more civs can be easier on high difficulty levels as it stops runaways civs. You only need to prepare and bribe warmongers and instead of amphitheaters built CBs

I think deity huge maps with designed peacefully cultural victory and with eg. 12 instead of 15 cultural and expansionist civs could be quite difficult.

From time to time on this forum someone say that had 'impossible' start but saves from those starts are never placed

Just realised, I said two then posted three.

That's given me idea for another one:

Iron man challenge
Stay awake for 36 hours before starting the game. Don't sleep till the game ends.