Make the minions have a itr/kind 8 in standing, walking, running, defending, punching (you can add more if you want).
This itr/kind 8 has to have y: somewhere high (999 for example) and a dvx leading to the explosion frame.
Then make explosion-activation frames that would start when you press DJA. In one of those frames put a bdy with y: at the same height as itr/kind 8 in minions and with width wide enough to cover the whole battleground.
So when you press DJA, the minions will react to the bdy and go to their explosion frame.
EDIT:
Never mind >.<
Listen to Lauli
This itr/kind 8 has to have y: somewhere high (999 for example) and a dvx leading to the explosion frame.
Then make explosion-activation frames that would start when you press DJA. In one of those frames put a bdy with y: at the same height as itr/kind 8 in minions and with width wide enough to cover the whole battleground.
So when you press DJA, the minions will react to the bdy and go to their explosion frame.
EDIT:
Never mind >.<
Listen to Lauli