This boss battle is the first time where AP and gil are earned after victory.
Tidus will seem hopelessly outmatched against the fast-moving fiend, but when its HP drops to half, a group of eccentrically-dressed individuals will bust into the hall and their leader will join the battle. A tutorial begins to explain two special skills available to "????": Steal and Use.
By this time Klikk will have returned to full health, but by having "????" steal and throw Grenades, the battle will be easily won. Tidus can now be used to deliver a few sword strikes, an Overdrive if and when one becomes available, and to use a Potion or two if necessary.