Monster Hunter 4: All S in Colosseum!

So I finally got all S in the Colosseum in Monster Hunter 4! And dang, that was hard.

Without a doubt, Kechawacha and the Rath couple.

 

 Kut-Ku is pretty simple and can be S-ed easily if you and your partner knows what to do. The easiest way is to simply choose the One-Handed sword for both partners and cut away until it dies. You should also aim to ride when you can, which isn't that hard thanks to the One-Handed's ability to climb-jump.

 

 Kechawacha
One of the harder ones. The main reason is that he moves a lot and at times, he goes up the vines. If he goes up there, he usually stays too long to get a S.
The easiest way to get S is double Light Bowgun. The other weapons all have really bad cutting edges. But for ranged weapons, this does not matter, as they have no edge. Also, the Light Bowgun can easily hit Kecha when he is hanging on the vines and drop him

Kenel Seltus and ArSeltus
Not really that hard, as long as you have a Bowgun. Best to have two?
Thanks to Kenel's size, Pierce Bullets are really effective. Once you take him out with Pierce, Ar is very easy.

Zabozagiru
Fairly difficult, though I can't figure out way. Anyways, the way I went about was using the Bow and its power pins. Just make sure you aim for the head and keep critical distance.

I had a great partner who knew what to do. The One-Handed Sword contains bombs and paralysis.
At the very start, place bombs in front of Tigrecks and blow up his face before the match starts. The first time he gets paralyzed, use the remaining big bombs again. After words, just chop at him like with Kut-Ku.

Zinogre
I find him difficult because of his amount of life. His Dragon ailment is also very annoying, so you definitely have to make sure to erase the ailment if you get hit.
My partner and I used a simple strategy. We both try to ride and I aim for the head. The weapons also have paralysis. Paralysis + Ride + Stun keeps Ogre from moving, so you can continue to deal damage to him.

Deviljho
Helped by the same partner as above, but he knew what to do and I assisted him.
The Bowgun shot at Joe's head and I aimed, as the hammer, towards Joe's head. My job was simple.
Not sure what my partner was doing, completely.

Rath couple.
Me and my partner tried so many times and FINALLY FINALLY got it. This is one hell of a difficult task, thanks to so many factors. You have to smoothly keep one away from the other, separated by the cage. You have to use Rides as much as possible to keep them down on the ground, because they love to float around where you can't hit them.
And both are just damn annoying enemies.
The best weapon for this seems to be the Great Sword. The main reason is not only their firepower, but because of their skill, which allows you to continue attacking even when the monsters are howling, which gives you a great advantage.
The Pink dragon is clearly the hardest, BTW.

 I wasn't really even aiming for this and got an S. I guess the main key is to hit both of them with the Dragon Spears at the side of the stage as well as hit both of them with the Bombs.
Other than that, ride a lot and attack a lot.