FFX2

First of all some info about the cat nip item.

Color: Gold
Ability: SOS ????
What it really does: All damages that you do when low in health (yellow) will be 9999
Description: "A seemingly ordinary jewel, but when the going gets tough..."
Sell price: 10 (DO NOT SELL)
Where: Via infinito cloister 40 ; Go to Bevelle after talking with Maroda enter the temple go to the right room.
When: Chapter 5

Ok so here is where this guide starts:

Get to chapter 5 Go inside Bevelle Then you will see Maroda and the kinderguardians, After a short scene go inside the temple, head to the right side of Bevelle's temple then you will see the kinder guardians again saying that they found something etc. You will see some kind of a logo and a save point, Step on the logo thing for a short scene where Pacce gets scared. After that, Step on the logo again and select the 1st option to go back then Save. Go back inside the Via infinito And move on. There will be mazes inside but its not that hard to figure out and by the way Charm bangles won't work here (WHYYYYY? T_T) Get all the way to Cloister 20 for a boss fight. But before that a warning, DO NOT FIGHT ELDER DRAKES when you are too low leveled. Elder drakes are the Red dragons that you see in some mazes (don't worry i dont think that they appear in random encounters.)
BOSS FIGHT:

Name: Aranea
Type: Crab
HP: 18280
MP: 178
Oversouled HP: 33394
Prefered Dress spheres: 2 Dark knights and 1 white mage that knows Cura, Reflect, Protect.
1 dark knight can be also changed to a Berserker for evade & hit skill.
Easiest boss in the Via infinito I promise.
Strategy:
Though this boss maybe easy beware of it. It can cast stop on you party and eat you O_O.
Cast Reflect/Protect. anytime within the first 3 rounds and for the other attackers just let them hit it.
Just keep praying or cure-ing and hitting with those two attackers and the battle will be over in a pinch.
When done Grab the Sphere it droppped and move on.

Keep going on through the mazes and Enter the Cloister 40
BOSS FIGHT: the one we were waiting for.

Name: Black Elemental
Type: Elemental
HP: 9999
MP: 2380
Oversouled HP: 10998
Prefered Dress spheres:
2 Dark knights with 5000+ HP and a white mage
OR
1 Gunmage with REALLY high str. 1 dark knight and 1 white mage.

Strategy:
Use dark knight's Charon in the first move FAST or Elemetilary if Gun mage.
If he manages to Ultima you on the first move then you just die

Kill him and then Get the cat nip in the treasure chest.