There is no way "henka" can be translated as "chained."
As I don't know Japanese, I was not talking about translation but about the real meaning of this kind of training. Sorry for confusion.
I think that in this case it shouldn't be translated literally.
In this training you don't apply random techniques, but you follow the behavior of attacker.Every time he counters your technique, you must create a situation, that his counter leads to another technique that you apply. In fact, you create a small opening in your techniques to teach him to find it so he can counter, and you both learn new skills.
This way the techniques are 'chained' one after another in very logic way.