Am I missing something here? (Omega DLC)

[xeemo]

So I've taken this guy down 3 times and he doesn't show up in my monsters list. Do I have to beat him within the target time limit or something?

 

[C i d]

So I've taken this guy down 3 times and he doesn't show up in my monsters list. Do I have to beat him within the target time limit or something?

The catch rate is quite rare, so you may need to kill it a few more times.

The target time isn't really related to the catch rate as far as I know.
There are 2 main ways to increase the odds.
1.) there's a fragment skill that increases catch rate by 20%
2.) finish him off using a feral link as the last move.