To obtain the first half of each character's limit break set, you have to kill a certain numberof monsters with that character. To get the second you need to use the first limit of that set a number of times.
But I was wondering could you complete both at once? Say for example I could say have Cloud on both the 2nd to last kill to gain Meteorain, and also the 2nd to last time of using Blade Beam to obtain Climicalhazzard and I ended up killing my last enemy with my last Blade Beam - would I get Metorain and Climicalhazzard at once?