It is in Vendetta's route we finally get the answer to what this 'victory' that we cant escape is. We can't escape our past. The realization of this and acceptance of past is victory. As long as Zephyr is alive his past will follow him and will always be with him together.
The past may be hard, painful but is it the reason to discard it? It is something that happened. People grow the most through pain, but what good is this pain, if you don't accept this happened? This applies to all characters, but not everyone has realized it.

I absolutely love the final battle and Zephyr and Vendetta's self-sacrifice, something that neither Kagutsuchi, nor Chris would be able to do, as first and foremost they were fighting for themselves, while Zephyr and Vendetta were fighting for their beloved and the past they shared together.