You can check here too: http://dreamcancel.com/wiki/index.php?title=K'_(XIII)
K’ doesn’t really have any gimmicks but he has some very solid tools. I can tell you how I play him, but really you’ll develop your own strategies and playstyle over time.
I think some good things to learn with K’ are pressuring with his cr.b which is great, getting a feel for his zoning/anti-air and the corner game. K has easy, safe blockstrings/combos off his cr.b and due to the range/speed of them, they are great to continue pressuring opponents. They combo into his trigger which is safe as far as I know, as long as you dont go into the shell/anti-air followup.
His fireball is good used sparsely from a distance I think. Midscreen it’s risky but I like to use it occasionally to bait out jumps then do the shell anti-air followup into qcb+k, dp+a for good damage on anti-airs. Of course he has the raw dp which is always useful too. Scare your opponent into playing safe and not jumping and that’s when you can start offense. He also has his chain drive super which does great damage and scares the opponent from using any fireballs against you.
His corner game is ridiculous in my opinion. His trigger doesn’t really push back in the corner, and being that it is safe on block you can really pressure people as long as you don’t play too obvious. Any cr.b in the corner leads to shell followup, qcb+k , dp+a which ought to make them scared to press buttons.
Anyways, i’m sure some other people think differently but you have to play more to figure out what works for you. K’ doesn’t have any remarkably bizarre mechanics or tools that set him apart aside from astonishing corner carries, but being very well rounded goes a long away in my opinion.