Pulling a target to you with chains or the fighters guild ability should always work although this was bugged up because of the change to the morph where you gap close to target. I understand the elevation restrictions on the gap close morph but there should never be an issue with pulling a target off a wall to you. I think the entire pvp community can agree if you are dumb enough to stand on the edge of a wall you should suffer the consequences of that risk. This is one of the iconic DK abilities that should work as originally intended as it does not allow player to bypass any of the mechanics in PVP.

I do believe that at one time blocking this ability caused you to be pulled to the target. I think that was fixed when they added the no cost cancel if not pulled to the caster.