Lunar Threads

I'm talking about the dogs in the Cave of Trials. I began thinking that it might be easier to power Alex up to Lv. 18 before Lann (fighting these in the Cave), rather than juice him up right before I go in the Crystal Tower to rescue Luna (which is when I usually get Alex to 18.)

Is there any pattern to their actions in battle?

It seems like when I target the dog in question with everybody in the party, it sticks around longer. I dunno if it's just crazy luck, or what. Anybody know the ratio of attack::escape in battle, or some pattern to their actions?

If you are around 15/16 and you use Alex's sword dance, they usually die, but they still have a chance of running.

It just seems like they let me kill them for a long time, then all of a sudden, they run from every single battle... Frustrating.