Champion All just researches all the champion technologies for cavalry, infantry, and archers.
If you are creating the unit during the game use army deploy instead of unit create and set it to convert once it is created. Make a ghost army for the titan of the player you want the titan to look like. Here would be the trigger:
Trigger 1
Condition: (whatever suits your needs)
Effect: Army Deploy - Titan (Greek player) - 1
Fire Event - Trigger 2Trigger2
Condition: Always
Effect: Army Convert - Titan's ArmyIf the Titan is already there at the start of the game, just put him in a normal army and use the same trigger 2, just no trigger 1.
Another thing, I hope it doesn't convert the titan to the other civilization's titan art. If it does, then you can't make a titan like it.