I discovered this during my first game of Fantasy this weekend (playing borrowed Bretonnians). I am probably not the first to discover it but I haven't seen anyone else post this so here it goes. Take a wizard with the Lore of Life, and give him/her a Power Scroll. You'll need to have at least eight dice in your pool for this to work. Use two dice to cast Throne of Vines, then use the Power Scroll to cast The Dwellers Below. You have a 90-something percent chance to get doubles which gives you Irresistible Force, but you can ignore the miscast on a 2+ with Throne of Vines.
It is by no means guaranteed and you shouldn't wrap a strategy around it but it is a good combo, especially against hordes.