Union Formations are the lifeblood of Yggdra Union, in which the "We'll Never Fight Alone" part of the title comes into practical application. Unions are used to attack groups of enemies en masse with ally units. Unionizing in itself is simple, yet it has a lot of tactical depth to it. Male units have an X formation while females have a + formation. You must align your units with the leader's union formation for them to charge alongside them. Also remember that the maximum number of units permitted in a union is five (5).
There is an order in which units charge when planning a union. It is optimal to memorize it. 1 will be the second unit to charge, followed by 2 and so-on. Although the priority numbering climbs to 8, always keep in mind that only five units can unionize at once. It is merely priority.