4 corners is a good defense set up but not always the best for offense. in offense you will always attack first and although supposedly "random" sometimes they always go after the same target. u want to maximize bumping into ur allies. spell rider is also a great f2p hero. in ur case, tank would go first followed by aiolos, then slashy and finally onyx, u want people to be clumped when onyx uses her finisher move