If we are calculating the odds of drawing two of our 20 Islands, we'd enter 20
So long as you keep foretelling cards and keeping your hand full so you can get that goad trigger, youll have yourself a hectic battlefield on your hands
You need to have the spells you want lined up in the graveyard already, and not be worried about anything else being exiled
As such, we needed a blue ability that is weak enough that using it ten-plus times isn't a problem, but that means enough that you care that you've done it ten times
Even just casting him on an opponents second turn with Leyline is perfectly reasonable
Less commonly, any time a player controls a permanent with nightbound, if it's neither day nor night and there are no permanents with daybound on the battlefield, it becomes day