Quick reaction is good not only in the Wild West (where the sole Secret Facility is Saloon, Colt Frontier Six-Shooter is used instead of Asteroids, while the only Minion is your horse). There are plenty of specialists in the space able to perform cunning tricks at breakneck speed! For instance... e-r-r-r... can’t find other examples... OK, for instance, me.
Oops, and another Villain — who used to rub hands foretasting some nasty success — finds himself among the ruins of his foolish hope. His Project failed to be completed on time, while the assault of his best Minion Operatives — successfully countered. Quick reaction rules!
Minion Ops with Reaction ability are played in response to certain actions of another Villain. These may be played during the other Villain’s turn, during your own turn (in theory), and basically at any time when the required condition is met.
In addition, you may play these Minion cards as regular Mobs. The Reaction ability pertains only to the Minion Ops.
—description from the publisher