Tatyana can be found in many of the towns all over the world. She sticks out very easily due to her appearance, and she'll chase you if she sees you. Tatyana's name changes everytime you meet her ( ie: Candy, Eclair etc). She's also the missing heir to the Lasiev Firm in Librof. She'll force her way into your party if she catches you three times unless you play as Mikhail. The only way to make her leave is to go to Librof. There's a switch that allows her to enter Librof, but I have no clue how to trigger it- and playing as Mikhail doesn't help since he can't get her. If anyone knows how to set the switch to activate other than hacking please email me.
Tatyana is actually a pretty decent character. She learns Epee wazas very fast but will take forever to master them. Her WP never really gets too high nor does her attack power. I guess the fact that she's a child hinders it. She's force to carry around her teddy bear which protects her from cold. I never really liked her much though.