[Autumn]

All you have to do is make sure spells that fling out multiple projectiles like hellspikes, Frayed voidgates and fleeing spectres don't copy past the first one sent out (Fleeing spectres seems to shoot out 8 per portal, cutting into someone's turn even lol)

Other than that, they all seem to shoot eastward and certain projectiles won't copy, Shinken and Crescent rook come to mind off the top of my head.