hmmm I don't know about this one Winni, it could be really abusive - if I understand correctly, this means you could ask them to give you all their cities and resources and they would have to accept - flipping it around, I would hate it if the AI did this to me and I'd probably concede the game right there.

I think they could take your concept and tone it down to a relationship boost or the perceived value of your offers is 50% better etc - but forcing the AI to accept any offer you make would be lame and it would massively suck balls if I was the victim of the AI casting this spell on me

On a side note I also play Magic the Gathering Online from time to time which is unfortunately being slowly wreaked by stupid OP cards and the card I hate the most in that game is called Mindslaver which basically lets an opponent take over your turn so not only do you miss a turn but the opponent will do everything they can to hideously gimp you using your own cards - your spell suggestion reminds me of this most hated card.

I was thinking of precisely that, DBG; the point of this spell is to knock one competitor down that's going to go down anyway.  I'm thinking the cost to do this has to be such that you've already won the game, it's now a matter of mopping up, and it's a fast, easy way to mop up.

Alternatively, limits could be placed on it so that the deal could be no more than 1000 points difference, or the spell fails.  You could force 1000 gold, or diplomacy points, or research points, or maybe a city worth 1000, but not more, but at the cost that you've now made a mortal enemy of that faction.  Maybe of every other faction, too.  Nobody likes anyone who uses mind magic.