i cant find him isnt he ment to be at the cavern of the stolen fayth
mayabe its becuase i got normal yojimbo at the end when u get controll the air ship?

Edit: Ugh... I must've fallen asleep... Here's what a guide says:

Dark Yojimbo

HP: 1600000
AP: 8000 (overkill: 10000)

Stats: Strength: 244 Defense: 210 Magic: 131 Magic Defense: 144
Agility: 243 Luck: 114 Evasion: 0 Accuracy: 255


Drops : Normal : 1(2) Dark Matter
Rare : 1(2) Master Sphere

Equipment (Drops 3-4 slots with 1-2 abilitites)

Auto-Abilities: Weapon: Counterattack, Magic Counter, Drive->AP, Break Damage
Limit
Break Damage Limit

Armor : Curseproof, Ribbon, Break HP Limit

Location : Caverns of the Stolen Fayth (Teleport to end then walk out)

Tactics : Firstly, you need to fight him 5 times by chasing the summoner back
to the entrance of the cave, you can save between fights but if you reload you
have to start all over again. So i recommend going to save points to recover
between fights. His attacks all have a chance of instantly killing your
characters by doing 99,999 damage, and his evade is very high so do Aim MANY
times. Quick hit is the way to go with back up from Blitz Ace and Attack Reel.
His attacks can also do status effects but i had ribbon so i am not sure what
they are. His overdrive attack is an instant kill and even if you have
auto-life, you will not be revived so using Aeons to block is a must.

I spaced out and starting talking about Valefor... I should get more sleep...

dark yojimbo is at cavern of the stolen fayth you can find him if you teleport to the back where you recieved his aeon, talk to him in aeon form.

then go to the save sphere and you should be stopped by a monk and dark yojimbo. keep fighting him and i think its after 5 fights that you win.

hope that helps