Ok I caught grondon so easy it makes kyogre look like a baby, I can't ctch..

You're just lucky, I used more that 200 pokeballs to catch him, yes pokeball-the red one. Use an ultra ball and a timer ball for catching kyogre.

If your having trouble then just use a master ball.
Or make it parlized and confused then use ultra or greatballs.

Get someone with false swipe and just weaken Kyogre to just one hp before barraging it with timer and ultra balls.

Try using a Timerball or netball,it could work.

Hey! I've notice legendaries and oter wild Pokemon are easier to catch with a great ball O.o don't ask it's wierd. Just try it, and before you catch it with just that tip, try this too! When you throw the ball, hold down and a when it opens to catch the Pokemon, I caught Mew with a pokeball doing that ^-^ gl!

Try to paralize it and get it HP down low,and then try to catch it.

I agree that catching Groudon is easy, I caught mine with a Dive Ball (the Lightblue one). But Kyogre is easy when you use powerful Pokemon to battle it but the best Pokeball I'd have to say to use on it is the Net Ball which you can buy at Mossdeep's Pokemart and to capture it is sorta hard I just brought my Slaking which is was at Lv 49 and Yawned him but the best strategies I'd have say would most effective would be Sleep, Paralize and Confusion don't burn or Poison it's impossible unless you have a miricle when you do that.

Net ball and or timer balls.