I was browing the NIN forums and noticed that Wintskitty is at a level where she can use a Gassan.
I'd never heard of this item so I looked up the quest details and thought I could handle it. Kitty's highest job is 30 thf, I figured that would be high enough to try out the Chocoboleech. I went up that hill in S Gusta and killed sheep for about 10 minutes and got the fresh blood. Then I ran off to Dangruf Wadi to see what I could do.
I found the ??? and cleared all the other leeches out so I wouldn't have any links. Cast Utsusemi and used a Meat Mithkabob and then traded the blood. The Chocoboleech spawned and I started swinging away. My hits were only doing 15-23 damage per, and once my shadows wore, he was hitting me for 25-35 and doing other nasty moves as well. Fortunately he was also missing me almost as often as he was hitting, so I managed to keep blink up here and there. After a particularly damaging TP move he did to me my HP was down to around 168. I hit perfect dodge, put my shadows up, and started wailing. 300% TP Gust Slash and our HP's were comparitively equal.
We continue bashing away at each other and I see a leech coming closer so I pull him away and we keep going at it. Finally when I was at 88 HP and fairly unsure of myself, I get 3 lucky crits in and he goes down. Got my new Katana and had a TON of fun with that fight. Most times, you can find a high level friend to come help you out but every once in a while you should strike out on your own, just to see if you can do it . There was a little extra incentive for me to win, if I had died I would have deleveled to 29.