Circle button on PS4
B button on XB1
Dunno what it is on PC.
Like for Miko, he puts his hands together and does a double palm shove. Its actually really fast, not the most damaging attack, but has actually decent knock back. You can spam it to practically juggle people for periods of time against a wall.
What about everyone else though? I haven’t felt like Quick/Off-hand Melee has been that effective for other characters.