Cathedral of Serra

W legendary creatures you control have "bands with other legendary creatures." (Any legendary creatures can attack in a band as long as at least one has "bands with other legendary creatures." Bands are blocked as a group. If at least two legendary creatures you control, one of which has "bands with other legendary creatures," are blocking/being blocked by the same creature, you divide that creature's combat damage, not its controller, among any of the creatures it's being blocked by/is blocking.)