/assist <p0>
/wait 1
/attack <t>Picks up whatever your party leader is fighting and attacks it. Keeps the whole party on one target without anyone calling it out loud.
Waits take whole seconds and snap to the server tick, so a one-second wait lands somewhere between roughly 0.8 and 1.25 seconds. Build in more slack than feels necessary.
/ja "Berserk" <me>
/wait 1
/ja "Aggressor" <me>