[With anyone else, Shadow Issei is servile - facing off against his other self, he projects a much more malicious air. With every word he speaks, Issei grows more and more upset, denying everything.]
You came to find me? That's odd. No one ever does. No one thinks of me, even those who should treat me as an equal. Should I start with the obvious? What about Emiya?
No- Don't you dare insult-
Don't dare insult kind and brave and dearly beloved Emiya Shirou who never thinks of us? You should realize now that I would never ever insult my love, who I would do anything for. I spent years never saying anything of my feelings to him even when they were painful, because it would bother him. And in return, when it was truly important? Who knew there was a Servant living in my house and never told me a word of this Holy Grail War? That person who I respected and cared for so highly that I wouldn't say anything to anyone about him assaulting me. My love can do me no wrong, for I deserve nothing higher than to be treated so.
I don't think like that of him...
My brother was a Master, before he died. Master to a dangerous Caster Servant who I can read well enough to know that all my sibling affection has gone to waste. It doesn't matter. Because I care for them, I have no choice but to accept whatever I am dealt by them, be it death or some measure of happiness.
Is home too painful? Then let me speak of being uprooted and placed into a world where everyone is stronger and wiser and better than me, where whenever I try to help I can do nothing. Even when our dearest friend here is in pain, I can barely get him to rest for a night. I can't soothe his true pain. I can't protect him no matter how much I try to wave a sword around. I can't do anything, because the truth of the matter is that I'm useless.
Be... be quiet...
If I were stronger. If I spent more time training and less time on myself. If I listened to them more and said the right things. If I did more, then they would surely give me their affection. Or at least, if I did anything they wanted, they would have to like me a little, wouldn't they? If I did more then Emiya would treat me as a best friend, Souichirou as a little brother, Diarmuid as an equal-
Stop it! I don't want to hear any more from you when you pretend to know what I feel! You are not me!
[He'll only be replying to action tags, at least until after the fight. He's a little busy.]