[A man who not only saved his life but will help him use weapons? Well, perhaps Kain is not as useless as he seems.]

Yes, thank you. I will certainly need some help...

[He tries to think of a good excuse for his stiff gait and lack of weapons experience. Revealing that this human body is absolutely nothing like his real body might hurt him.]

The gravity of this place... I'm not used to moving around in it.

[Well no, he'd be moving a bit differently if that was actually the case, but the average layperson wouldn't know that.]

Using a weapon will be a new experience.