Then Walker agreed to this.

[It's not a question, but despite how badly he tends to think of Allen Walker, it's not accusing either. It's only a statement.

This explains the feeling of helplessness though. There isn't a plausible way around this that is even remotely ethical unless they can get him back into his old vessel.]

How "damaged" is the old vessel? There are people here who can quickly repair plenty of injuries. Someone must have thought of that by now.