unionall.ssb is a file, containing the game's coroutines. Those coroutines are used to show a cutscenes, return controls to the player after the dialogue with NPC, make a Cutscene -> Overworld transition etc. You can call those coroutines with CallCommon, JumpCommon and supervision_ExecuteCommon opcodes.

Coroutines

coro END_TALK

coro WAIT_START_FUNC

coro NORMAL_WAIT_END_TALK

coro LIVES_REPLY_NORMAL

coro LIVES_REPLY

coro OBJECT_REPLY_NORMAL

coro LIVES_ACTING_NORMAL

coro ENTER_WAIT_FUNC

coro TALK_UNIT

coro TALK_ADVENTURE

coro TALK_ATTENDANT

coro TALK_PARTNER_MESSAGE

coro LIVES_MOVE_NORMAL

coro LIVES_MOVE_CHANGE=

coro LIVES_MOVE_PARTY

coro OBJECT_MOVE_NORMAL

coro OBJECT_MOVE_CHANGE

coro PERFORMER_MOVE_NORMAL

coro PERFORMER_MOVE_CHANGE

coro MOVE_INIT

coro MOVE_PAUSE

coro MOVE_STAY

coro MOVE_SLEEP

coro MOVE_RANDOM

coro MOVE_TYPE1

coro MOVE_TYPE2

coro WAKEUP_FUNC

coro WAKEUP_FUNC_SERIES

coro LOOK_AROUND_FUNC

coro LOOK_AROUND_FUNC_SERIES